UPSC ONLINE ACADEMY

Raashid Shah

AGES SET-2

Q.1 Ratio of the ages of the father & the son at present is 6:1. After 5 years ratio will become 7:2. What is the present age of the son ?   A) 30 yrs   B) 31 yrs   C) 32 yrs   D) 33 yrs   Ans. A   Sons’s age = Y * T(a-b) / difference of cross product   Or  1 * 5 (6-1) / 12 – 7   5*5 / 5 = 5 yrs   Father’s age = X *T (a-b) / Difference of cross product   6*5 (6-1) / 12-7   =6*5 = 30 yrs   Q.2 10 yrs back sum of the ages of a mother & her daughter is 45. If the ratio of their present ages be 9:4. Then the present age of the daughter is :-   A) 20 yrs   B) 21 yrs   C) 22 yrs   D) 23 yrs   Ans. A   10 yrs back, D + M = 45   Now, at present, D + M =45+10 = 55   Thus, 9x+4x=55   13x=55       Or x=5   Or D=4x = 20   Q.3 Suresh’s father is 2yrs older than his mother. His age is 3yrs less than half of his mother ago. He was born when his father was 23yrs old. Find the age of Suresh ?   A) 14yrs   B) 15yrs   C) 16yrs   D) 17 yrs   Ans. A   F = 2 + M   M = F – 2   Or S = M/2 – 3   F-2/2 – 3   Or F-8/2   Or F = S+23   = 23 + F-8/2   Or F = 37+F / 2   F = 37   Now, Suresh’s age = 37-23 = 14 yrs   Q.4 Three years earlier father was 7 times as old as his son. Three years hence, father’s age would be four times that of his son. What is the present age of son ?   A) 9 yrs   B) 10 yrs   C) 11 yrs   D) 12 yrs   Ans. A   Shortcut:   T2(z-1) + T1(x-1)   3(4-1)+3(7-1) / 7-4   = 9yrs Q.5 Peter is twice as old as Paul was when Peter was as old as Paul is now. The combined age of Peter and Paul is 42years. How old is peter now?   A) 21   B) 28   C) 24   D) 26   Ans. B     peter’s age = x   paul’s age = y   x+y =42   Since, x=2y, then x+2y=42 3y = 42 y=14 i.e. Paul’s age   Or Peter’s age = 28 years      

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CP & SP SET 6

  Q.1 If selling price of an article is   of its cost price, the percentage profit in the transaction isA)  %B) 98 %C) 33  %D) None of theseAns. C S.P. = 4/3 C.P. Profit = S.P. ??C.P. =   C.P. – C.P. =  %profit =   x 100 = 33 % Q.2 By selling a doll at $342, Mac lost 5%.At what price should he have sold it to gain 5%? A) $378B) $380C) $410D) $462 Ans. A If cost price of the doll is x, 0.95 x = 342? x =   = $360Now to gain 5%, new selling price = 1.05 x 360 = $378Q.3 If a dealer were to diminish the selling price of his wares by 10% he would double his sale making the same profit as before . In what ratio his profit diminsh if he were to increase his selling price by 10% and thereby half his sale A) 20 %  B) 25 % C) 30 % D) 35 % Ans. B Let CP of each article be ‘x’, SP of each article be ‘y’ and nos. of articles sold be ‘z’.therefore, profit = z*(y-x) case 1: Profit (P1) = z*(y-x) = 2z*(0.9y – x)solving for x and y we get:x = 0.8y ……………eq.1 therefore P1 = 0.2yz….eq.2 case 2:Profit P2 =  0.5z*(1.1y – x) ……….eq.3putting eq.1 in eq.3 we get:P2 = 0.15yz therefore ratio of diminishing profit = (P1 – P2)/P1 = 1/4 or 25% 🙂  Ratio of diminishing profit: 1/4. % of diminishing profit = 25% Q.4 How much percent must be added to the cost price of goods so that a profit of 20% must be made after giving a discount of 10% from the market price? A) 33 1/3 B) 32 1/3 C) 33 ½ D) 32 ½ Ans. A Let Mp= 100 RsSp after 10% discount = 100*90/100=90to have profit of 20%.120% CP=selling priceCP=SP/120*100=90/120*100=75RsMP is 25Rs more than Cppercentage added amount =25/75*100=33 1/3% Q.5 A trader mixes 26 kg of rice at Rs. 20 per kg with 30 kg of rice of other variety at Rs. 36 per kg and sells the mixture at Rs. 30 per kg. His profit percent is:A) No profit & No lossB) 5 % C) 8 %D) 10 %Ans. B Explanation:C.P. of 56 kg rice = Rs. (26 x 20 + 30 x 36) = Rs. (520 + 1080) = Rs. 1600.S.P. of 56 kg rice = Rs. (56 x 30) = Rs. 1680.  Gain = 80 x 100 % = 5%.1600        

CP & SP SET 6 Read More »

AGES SET-1

Q.1 Present ages of Anu and Raj are in the ratio 4:5. Eight years from now the ratio of their ages will be 5:6. Find the present age of Raj ?   A) 38   B) 39   C) 40   D) 41   Ans. C   Let the present ages of Anu and Raj be 4x years and 5x years respectively. After eight years. Anu’s age = (4x + 8) years; After eight years, Raj’s age = (5x + 8) years. Therefore, the ratio of their ages after eight years = 4x + 8 /  5x + 8 This is given to be 5 : 6 Therefore, 4x + 8/ 5x + 8 = 5/6 Cross-multiplication gives 6 (4x + 8) = 5 (5x + 8) or 24x + 48 = 25x + 40 or 24x + 48 – 40 = 25x or 24x + 8 = 25x or 8 = 25x – 24x or 8 = x Therefore, Anu’s present age = 4x = 4 × 8 = 32 years Raj’s present age = 5x = 5 × 8 = 40 years   Q.2 A grandfather is ten times older than his granddaughter. He is also 54 years older than her. Find their present age of Grandfather ?   A) 50 yrs   B) 60 yrs   C) 61 yrs   D) 62 yrs   Ans. B   Let the granddaughter’s age be x years. Therefore, grandfather’s age will be 10x years. According to the question, Grandfather’s age = Granddaughter’s age + 54 years 10x = x + 54 Transposing x to L.H.S, we obtain 10x – x = 54 9x = 54 x = 6 Granddaughter’s age = x years = 6 years Grandfather’s age = 10x years = (10 × 6) years = 60 years   Q.3 10 yrs ago the sum of the ages of two brothers was equal to one-third of the age of their father. Elder brother is 2yrs older than the younger . At present the sum of their ages is less than the age of the father by 14yrs. What is the age of the father ? A) 46 yrs B) 47 yrs C) 48 yrs D) 49 yrs Ans. A Let the age of father, elder son & younger son be x,y & z yrs Therefore, y-10+z-10 = 1/3(x-10) Or 3y-30+3z-30 = x-10 Or –x+3y+3z = 50—–i y-z = 2—–ii x-(y+z) = 14 x-y-z = 14—-iii Multiply equation iii by 3 & then add equation I, we get 2x = 92 X=92/2 = 46   Q.4 The age of the father 3yrs ago was 7 times the age of his son. At present the father’s age is five times that of his son. What are the present ages of the father & the son ?   A) Father’s age=45 yrs , Son’s age=9 yrs   B) Father’s age=46 yrs , Son’s age=10 yrs   C) Father’s age=47 yrs , Son’s age=11 yrs   D) Father’s age=48 yrs , Son’s age=12 yrs   Ans. A   Shortcut:   Sons’s age = T1 (x-1) / (x-y)   18/2 = 9 yrs   In the same way, we have   Father’s age = 45 yrs   Q.5 Sum of the ages of the mother & her daughter is 50 yrs. Also 5 yrs ago, the mother’s age was 7 times the age of the daughter. What are the present ages of the mother & the daughter ?   A) Mother’s age= 40 yrs. & Daughter’s age= 9   B) Mother’s age= 41 yrs. & Daughter’s age= 10   C) Mother’s age= 40 yrs. & Daughter’s age= 10   D) Mother’s age=39 & Daughter’s age=10 yrs.   Ans. C   Shortcut:   Daughter’s age = S1+T1 (N1-1) / N1+1   50+ 5(7-1) / 7+1   10 yrs   Or Mother’s age = 50-10 = 40 yrs   NOTE: If there will be after…….years like”after 5 years” in place of ago like “5 yrs ago”, then use this formula:   S1-T1(N-1) / N1+1  

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CP & SP SET 5

Q.1 A watch passes through three hands and each gains 25%. If the third sells it for $250, what did the first pay for it (in $)?A) 102B) 117C) 128D) None of theseAns. C If first person paid $x for the watch, S.P. of first person = C.P. of second person = 1.25xS.P. of second person = C.P. of third person = 1.25 × 1.25xS.P. of third person = 1.25 × 1.25 × 1.25x = 250? C.P. of first = = $128 Q.2 A dishonest shopkeeper professes to sell pulses at the cost price, but he uses a false weight of 950gm. for a kg. His gain is how much % A) 5.3 % B) 4.3 % C) 5.1 % D) 4.1 % Ans. A shortcut,Learn this formula: Error/True weight- Error *100Let True weight is 1000 Error=950 (Given)Therefore,1000-950/1000-(1000-950)*100(Error is calculated as = True weight -Error)=5.26 % or 5.3 % Ans. Q.3 A man buys 1000 items at $3 each. He sells 700 of them at $4.50 each, and the rest at $2.50 each. Find his average profit per item sold. A) $0.90 B) $900 C) $1.285 D) $1.50 Ans. A A man buys 1000 items for $3 eachTotal cost or C.P. = 1000 3 = $3000Total selling price of 700 items at 4.50 = 700 4.50 = $3150And selling price of rest of the items i.e. (1000 – 700) at 2.50 = 300 2.50 = 750Total S.P. = 3150 + 750 = 3900Now profit = 3900 – 3000 = 900Average profit = = = $0.90 Q.4 A bought 20 kg of sugar at the rate of Rs. 8.50 per kg and 30 kg of sugar at the rate of 9.75 per kg. He mixed the two. At what price per kg should he sell the mixture to get 25% profit on the cost price? A) Rs.11.50 B) Rs.12.50 C) Rs.10.50 D) Rs.10.00 Ans. AApply direct formula :Selling price of the mixture = {(20 × 8.5 + 30 × 9.75}/50 × 1.25 = 11.56 Q.5 A bought 20 kg of sugar at the rate of Rs. 8.50 per kg and 30 kg of sugar at the rate of 9.75 per kg. He mixed the two. At what price per kg should he sell the mixture to get 25% profit on the cost price?A) Rs.11.50B) Rs.12.50C) Rs.10.50D) Rs.10.00 Ans. A Apply direct formula :Selling price of the mixture = {(20 × 8.5 + 30 × } × 1.25 = 11.56 ??11.50    

CP & SP SET 5 Read More »

CP & SP SET4

Q.1 A reduction of 40% in the price of bananas would enable a man to obtain 64 more for Rs. 40. What is the reduced price per dozen ? A) Rs. 3 B) Rs. 5 C) Rs. 8 D) Rs . 9 Ans. A He purchases 64 more bananas for 40% of Rs. 40 or Rs. 16 Therefore, reduced price per dozen = 16/64 * 12 = Rs. 3Q.2 A man buys 5 horses & 10 cows for Rs. 1600. He sells horses at a profit of 15% & cows at loss of 10%. If his overall profit was Rs.90,what was the cost price of horse & cow ? A) 100 B) 200 C) 300 D) 400 Ans. B Let x be cost price of horse & y be the cost price of cowTherefore, C.P. of 5 horses = Rs.5xC.P. of 10 cows = Rs. 10yThus, 5x+10y = 1600 —-1Since Profit is 15% on the horsesTherefore, Profit on the sale of Rs.5x = 15*5x/100 = 3x/4Similarly, Loss on the cows is 10 % Thus, Loss on the sale of Rs. 10y = 10y*10/100=yAgain,Profit on horses – Loss on cows = Rs. 903/4x – y = 903x-4y = 360—-2Thus on solving these two equations, we getX = Rs. 200 Q.3 A man brought a merchandise whose price was listed at Rs. 160. He was given successive discounts of 20% & 10%. What price he paid for the merchandise ? A) 115.20 B) 116.0 C) 115.0 D) 116.20 Ans. A Since he was given at first discount of 20%100-20 = 80 Therefore, If Rs. 100 is listed price, then S.P. = Rs. 80 & If Rs. 160 is listed price then S.P. = 80/100*160 = Rs.128 He was again given a discount of 10%100 – 10 = 90 If Rs. 100 is the listed price, S.P.is Rs. 90 If Rs. 128 is the listed price, S.P. is Rs.90/100 *128= 115.20 Q.4 A dealer allows 10% discount on the list price of a certain article & yet makes a profit of Rs.25% on each article. Find the cost price of the article when the list price is Rs. 50. A) 34 B) 35 C) 36 D) 37 Ans. C Let C.P. of the article be Rs. 100Then for 25% profit S.P. = Rs.125—-iIf list price is Rs.100, S.P. = Rs. 90—-iiIf S.P. is Rs. 90, List Price = Rs. 100 If S.P. is Rs. 125, List Price = 100/90*125 = 1250/9 If list price is Rs. 1250/9, then C.P. = Rs.100 If list Price is Rs. 50, then C.P.= 100*50*9 / 1250 = Rs. 36 Q.5 A carpenter undertakes to supply 2000 tables at Rs. 17.25 each. He estimates that if 10% are defective which will be sold at 50%, then the profit will be 15% on his whole outlay. When the tables were supplied 70% of the tables were found defective. What loss did the carpenter incur ?A) Rs. 6075B) Rs. 7800C) Rs. 16075D) Rs. 4666Ans. A10% of 2000= 200S.P. of 200 tables at 50 % = Rs. 200*17.25/2= Rs. 1725S.P. of remaining 1800 tables=Rs. 1800 * 17.25= Rs. 31050Rs. 31050+1725= Rs. 32775Now, Rs. 32775 includes 15 % profitTherefore, C.P.= 100 / 115*32775 =Rs. 28500Now, the actual S.P.=2000*30/115*17.25+2000*70/100*17.25/2= 2000* (30/100 + 35/100) * 17.25=20*65*17.25= Rs. 22425Therefore, Loss = C.P. – S.P. = 28500 – 22425= 6075    

CP & SP SET4 Read More »

CP & SP SET3

Q.1 The C.P. of 6 tables is equal to the S.P. of 4 tables . What is the Profit % A) 47 % B) 48 % C) 49 % D) 50 % Ans. D Shortcut: x-y/y * 100 or 6-4/4 * 100 = 2/4*100 = 50% Q.2 A machine is sold for Rs. 5060 at a gain of 10 %. What would have been the gain or loss % if it had been sold for Rs. 4370 ? A) 5 % B) 6 % C) 7 % D) 8 % Ans. A Shortcut : C.P. = 100/110 * 5060 = Rs. 4600 In this case there is always loss % Loss% = C.P – S.P. / C.P. * 100 Or 5% Q.3 Mohan sold a book at a profit of 6%. Had he sold it for Rs. 2 more he would have gained 10% C.P. of books ? A) 50 B) 51 C) 52 D) 53 Ans. A Q.4 A man sold two houses for Rs. 800000 on one he gains 20 % while on the other he losses 20%. How much does he gain or loss in the whole transaction ? A) 4 % B) 5% C) 6 % D) 7 % Ans. A Shortcut: (20/10)2 = 4 % Q.5 A shopkeeper marks his goods at 20% above his cost price & allows purchases a discount of 10 % for cash . What profit % does he make ? A) 6 % B) 7 % C) 8 % D) 9 % Ans. C Shortcut: x-y-xy/100 % 20-10-200/100 =8 %      

CP & SP SET3 Read More »

CP & SP SET2

Q.1 Person purchases 100pens at a discount of 10%. Then net amount of money spent by the person to purchase the pens is Rs.600. The selling expenses incurred by the person are 15% on the net cost price. What would be the S.P. for 100 pens in order to earn a profit of 25% ?A) Rs. 875B) Rs. 811C) Rs. 862.50D) Rs. 802.50Ans. CTotal cost price = 600+15% of 600=600 + 600 * 15/100Rs. 690Profit = 25%Thus, S.P.=C.P. [100+profit / 100]Or 690[100+25 / 100] 690*125/100 = Rs.862.50 Q.2 Left pan of a faulty weighs 100 gms more than its right pan. A shopkeeper keeps the weight measure in the left pan while buying goods but keeps it in the right pan while selling his goods. He uses only 1kg weight measure. If he sells his goods at the listed cost price, what is his gain % ?A) 200/9 %B) 100/11 %C) 200/11 %D) 1000/9 %Ans. CLet purchased amount be 1100 g & the cost price of 1100 g be Rs. xTherefore, he pays for 1000 g & buys 1100gCost Price of 1000g = Rs.10/11xTherefore, net profit = Rs.x/11Similarly while selling if he sells 1000g. He would actually be selling 900kg at the price of 1000kgSimilarly, once again the profit would be Rs. x/11Therefore total profit = Rs.2x/11 * 100In terms of percentage ,this would be 200/11% Q.3 A man purchase 8 pens for Rs. 9 & sells 9 pens for Rs.8. How much Profit or Loss % ? A) 20.98 % B) -20.98% C) 19.98 % D) 19.98 % Ans. B Shortcut: 8 9 9 8 = 64-81 / 81 = -20.98 % Since it is in negative that’s why it is Loss % Q.4 A dishonest dealer uses a weight of 950 gm for 1 kg gain % ? A) 5.26 % B) 6.26 % C) 5.30 % D) 6.30 % Ans. A Shortcut: Error / true value * 100 = 1000-950 / 1000-(1000-950) * 100 50/950 * 100 = 5.26 % Q.5 A shopkeeper sells his product at a profit of 10 % & uses a weight which is 20 % less. What is the total gain % ? A) 39.7 % B) 37.5 % C) 40.20 % D) 36.2 % Ans. B Shortcut : Gain % + % less in weight / 100 – % less in weight * 100 10+20/100-20 * 100 30/80*100 = 37.5 %    

CP & SP SET2 Read More »

CP & SP SET1

Q.1 One typewriter marked for sale at Rs. 480. A dealer allows a discount of 10% & yet makes profit of 8%. What should his gain if no discount were allowed ?A) Rs. 38B) Rs. 48C) Rs. 20D) Rs. 80Ans. DLet C.P. of typewriter is Rs.= 100Profit = 8 %Therefore, S.P. = Rs. 108Since discount = 10%Hence if Rs. 100 is the marked price , then S.P.= Rs. 90If Rs. 90 is S.P. then marked price = Rs. 100Therefore, If Rs. 108 is S.P., then marked price = 100 * 108 / 90= Rs. 120If Rs. 120 is the marked price & no discount is allowed then Profit = Rs. 20 (Since 120-100=20)If Rs. 480 is the marked price then profit = 20 * 480 / 120 = Rs. 80 Q.2 Mohan sells two horses for Rs. 1955 each. On one of them he gains 15 % & on the other he losses 15 %. Find the total gain or loss ?A) Loss of Rs. 90B) Gain of Rs. 90C) Profit of Rs. 150D) No loss & no profitAns. AProfit on one horse = 15 %If S.P, is Rs.115, then C.P. = Rs.100Hence if S.P. is Rs.1955, then C.P.= 100 * 1955 / 115= Rs. 1700On the other horse, since loss = 15 %Hence if S.P. is Rs.85, then C.P. = Rs. 100Hence if S.P. is Rs. 1955, then C.P. = 100 * 1955 / 85Rs. 2300Therefore, C.P. of both the horses = 1700 + 2300= Rs.4000& S.P. of both the horses = 1955 + 1955 = 3910Thus, actual loss on both the horses = 4000 – 3910 = Rs. 90 Q.3 A dishonest shopkeeper deceives by 15% at the time of purchase of the article & also 15 % at the time of sale . Find out the % of profit ?A) 15%B) 32 ½ %C) 33 %D) 30 %Ans. BLet he purchase goods of Rs. 100If Rs. 100 goods is sold in Rs. 115Therefore, 115 goods is sold in Rs. 115 * 115 / 100 = 23 * 23 / 4= 132Hence profit = 132 ¼ – 100= 32 ¼ % Q.4 A person purchases 90 clocks & sells 40 clocks at a gain of 10% & 50 clocks at a gain of 20%. Had he sold all of them at a uniform profit of 15 % he would have got Rs. 40 less. Find the cost price of each clock ?A) Rs. 70B) Rs. 80C) Rs. 90D) Rs. 100Ans. BLet C.P. of clock be Rs.100 eachBy profit of 10% S.P. of 40 clocks = 110*40 = Rs. 4400By profit of 20% S.P. of 50 clocks = 120 *50 = Rs. 6000Total S.P. = Rs. 4400 + 6000= Rs. 10400C.P. of 90 clocks = 90 * 100 = Rs.9000By profit of 15% S.P. of 90 clocks = 90 * 115 = Rs. 10350Difference = 10400 – 10350=Rs. 50If the difference is Rs. 50, then C.P. = Rs. 100If the difference is Rs. 40 then C.P. = 100 * 40 / 50=Rs. 80 Q.5 A trader sold 20 p.c of his stock at 10 p.c profit & 50 p.c of the remainder of his stock at 10 p.c. loss. What would be the rate of profit for sale of the remainder of his stock in order that the trader may make an overall profit of 5 p.c. over his entire stock ?A) 17.5%B) 17.2%C) 18.5%D) 18.2%Ans. ALet C.P. of entire stock is Rs.100Therefore C.P. of 20% stock = 100 * 20 / 100 =Rs. 20This stock is sold at 10% profit .S.P. of this part of stock = 110 * 50 / 100 =Rs. 22Now,50 % of this remainder = 80 * 50 / 100= 40% of the entire stockC.P. of this part of stock =Rs.40S.P. of this part of stock =Rs.90 * 40 / 100 =Rs. 36& S.P. of the entire stock at 5% profit= 105 * 100 / 100 =Rs. 105Therefore, S.P. of remainder = 105 – (22+36) = Rs. 47& C.P. of the remainder = 100-20-40=Rs.40Therefore, rate of profit of the remainder = (47-40) * 100 / 40=17 * 100 / 40 = 17.5% Ans.      

CP & SP SET1 Read More »

TIME & WORK SET 8

Q.1 A piece of work can be done by 5 men or 9 women in 19 days. In how many days, will 3 men and 6 women complete the same piece of work? A) 15 days B) 4 days C) 6 days D) 12 days Ans. A Five men or 9 women (5 M = 9 W) can do the job = 19 days (Given)3M = 27/5 W3 men and 6 women = (27/5 + 6 = 57/5 women) 57/5 womenTime taken by 57/5 women to complete the work = 19 × 9 × 5/57 = 15 days. Q.2 A contractor undertook a certain work to be done in 80 days and employed 72 men to do it. After 20 days he found that 1/3rd of the work has been finished. How many men should he dismiss in order that the work may be finished on the date agreed upon?A) 48 menB) 72 menC) 24 menD) 36 men Ans. C72 person can finish rd of work in 20 days.It mean they can complete the remaining job in 40 days.Now according to the questions40 × 72 = (72 – x) 6072 – x = 48x = 24 To complete the work in 60 days, contractor has to reduce 24 men. Q.3 The time required by A to complete a piece of work is times the time required by B to complete the same piece of work. If A and B work together, they take 16 days less than the time taken by A alone to complete the piece of work. How many days will B alone take to complete the piece of work?A) 20 daysB) 40 daysC) 60 daysD) 80 daysAns. C Assume B can do the work in ‘d’ days.So, A needs d days.A and B together need = days.It is given – = 16d = 60 days. Q.4 ‘C’ can do as much work in 1 day, as A and B together can do in the same period of time. A alone can do the same piece of work in 12 days, whereas B alone can do it in 16 days. If B and C work together, how many days will they take to complete the piece of work?2A) 3 daysB) 4 daysC) 5 daysD) 3 daysAns. BA can do part of the work in 1 day.B can do part of the work in 1 day.So, C can do = part of the work in 1 day.So, B and C can do = in 1 day.So, it takes = 4 days. Q.5 Rahul is sailing at a uniform speed when a leak develops in his boat. He uses a bucket to empty water from the boat and reaches the shore in 30 minutes just in time to avoid sinking. The leak fills the boat twice as fast as the Rahul is able to empty it. Had the leak developed 10 minutes earlier how much faster would the Rahul have had to work to reach the shore safely?A) 20 %B) 25 %C) 30 %D) 35 %Ans. BLet r = rate of removing water from the boatthen2r = rate of water leaking into the boatlet a boat full of water, ready to sink = 130/r – 30/2r=12(30) – 30 = 2r60 – 30 = 2r30 = 2rr = 15 rate of removing water from the boat:Find the rate if leak occurs 10 min earlier (40 min to the shore)40/r-40/2r=12(40) – 40 = 2r2r = 40r = 20 rate of removing water from the boatI guess you could say remove the water; 5/15 = 33% faster Q.6 A does a work in 90 days, B in 40 days and C in 12 days. They work one after another for a day each, starting with A followed by B and then by C. If the total wages received is Rs. 360 and A, B and C share it in the ratio of the work done, find their respective individual wages. A) Rs. 40, Rs. 60 and Rs. 260B) Rs. 36, Rs. 81 and Rs. 243C) Rs. 42, Rs. 86 and Rs. 232D) None of theseAns. B 1/90+1/40+1/12=43/360 43*8/360=344/360 so 16/360 -1/90=1/40 1/40-1/30=1/120 1/120/1/12=1/10 9*1/90:9*1/40:81/10*1/12 4:9:27 4/40*360=369/40*360=8127/40*360=243 Q.7 In one day a man can do twice the amount of work done by a child in a day. It takes 40 days for 50 children working for 8 hours a day to complete the piece of work. If 40 men work for 5 hours a day, how many days will it take them to complete the same piece of work?A) 40 daysB) 60 daysC) 80 daysD) 10 daysAns. C 20 men is equivalent to 90 children.= = = d2 = 80 days. Q.8 In how many ways 19 people can be seated around two round tables with seating capacities of 9 & 10 people.A) 19!/9!B) 8!/9!C) 19C9*8!*9!D) 2*19C9*8!*9!Ans. DOut of two tables , 1 table can be selected in 2 ways.Out of 19 people , 9 people can be selected in 19C9 ways & 9 people can be arranged around a circular table in 9-1= 8! Ways.Also, 10 people can be arranged around a circular table in 10-1=9! Ways.Therefore, Total no. of ways=2*19C9*8!*9!  

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TIME & WORK SET 7

Q.1 It was calculated that 75 men could complete a piece of work in 20 days. When work was scheduled to commence, it was found necessary to send 25 men to another project. How much longer will it take to complete the work? A) 30 B) 40 C) 50 D) 60 Ans. A Explanation:Before:One day work = 1 / 20One man’s one day work = 1 / ( 20 * 75)Now:No. Of workers = 50One day work = 50 * 1 / ( 20 * 75)The total no. of days required to complete the work = 1/ 30 or 30 days Q.2 A man was engaged on a job for 30 days on the condition that he would get a wage of Rs. 10 for the day he works, but he have to pay a fine of Rs. 2 for each day of his absence. If he gets Rs. 216 at the end, he was absent for work for how many days ? A) 5 days B) 6 days C) 7 days D) 8 days Ans. CExplanation:The equation portraying the given problem is:10 * x – 2 * (30 – x) = 216 where x is the number of working days.Solving this we get x = 23Number of days he was absent was (30-23) i.e.7 days. Q.3 A contractor agreeing to finish a work in 150 days, employed 75 men each working 8 hours daily. After 90 days, only 2/7 of the work was completed. How many men should be increased, each working now for 10 hours daily, so that the work can be completed in time. A) 140 B) 150 C) 160 D) 170 Ans. B Explanation:One day’s work = 2 / (7 * 90)One hour’s work = 2 / (7 * 90 * 8)One man’s work = 2 / (7 * 90 * 8 * 75)The remaining work (5/7) has to be completed within 60 days, because the totalnumber of days allotted for the project is 150 days.So we get the equation(2 * 10 * x * 60) / (7 * 90 * 8 * 75) = 5/7 where x is the number of men workingafter the 90th day.We get x = 225Since we have 75 men already as given in the question,Then, 225-75= 150 Q.4 It takes Mr. Karthik y hours to complete typing a manuscript. After 2 hours, he was called away. What fractional part of the assignment was left incomplete? A) (y – 2) / y B) 1-y/2 * y C) y-2 D) None of the above Ans. A Explanation:To type a manuscript karthik took y hours.Therefore his speed in typing = 1/y.He was called away after 2 hours of typing.Therefore the work completed = 1/y * 2.Therefore the remaining work to be completed = 1 – 2/y.(i.e.) work to be completed = (y-2)/y Q.5 If 3 houses are to be painted, Mr. A can paint a house in 6 days (nos are not same) Mr. B can do the same in 8 days & Mr. C in 12 days. If Mr. A does the work for 8 days & leaves for vacation, & Mr. B continues the work for the next 6 days, for how many days should Mr. C work? A) 10 B) 11 C) 12 D) 13 Ans. B 1/6 * 8 + 1/8*6 + 1/12 * x =3Multiply by common denominator of 24 32+18+2x = 7250+2x=722x=22X=11      

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