UPSC ONLINE ACADEMY

Raashid Shah

AREA MCQS SET-1

Q.1 A gardener increased the area of his rectangular garden by increasing its length by 40% & decreasing its width by 20%.The area of the new garden A) has increased by 20% B) has increased by 12% C) has increased by 8% D) Same as the old area Ans. B Explanation:The area of the new garden==(40-20- 40*20/100)%=(20-80)%=12% Q.2 There is a narrow rectangular plot, reserved for a school, in Mahuli village. The length and breadth of the plot are in the ratio 11:4. At the rate Rs100 per metre it will cost the village panchayat Rs 75000 to fence the plot. What are the dimensions of the plot? A) 274 & 100 m B) 275 & 200 m C) 275 & 100 m D) None of the above Ans. C Let the common ratio between the length and breadth of the rectangular plot be x. Hence, the length and breadth of the rectangular plot will be 11x m and 4x m respectively.Perimeter of the plot = 2(Length + Breadth) It is given that the cost of fencing the plot at the rate of Rs 100 per metre is Rs 75, 000.? 100 × Perimeter = 75000100 × 30x = 750003000x = 75000Dividing both sides by 3000, we obtainx = 25Length = 11x m = (11 × 25) m = 275 mBreadth = 4x m = (4 × 25) m = 100 mHence, the dimensions of the plot are 275 m and 100 m respectively. Q.3 A Village having a population of 4000 requires 150 litres of water per head per day. It has a tank measuring 20m x 15m x 6m. The water of this tank will last for A) 2 days B) 3 days C) 4 days D) 5 daysAns. BTotal amount of water for 4000 people=4000*150=6,00,000 ltrs.=600 m3Volume of tank= 20m * 15m * 6m=1800 m3Therefore,required no. of days=1800/600 =3 Q.4 Cost of carpeting a room 8m long & 4m wide with a carpet 2m wide is Rs.50 per metre. Find the cost of carpeting the floor?A) Rs. 650B) Rs. 700C) Rs. 750D) Rs. 800Ans. DLength = L * B/ Width of carpetOr 8 * 4 / 2=16mNow, Cost = 16*50 = Rs.800 Q.5 A garden is 112m long & 78 m wide. It has walking path 25m wide all around it on inside. Find the area of path ?A) 925 m2B) 927 m2C) 929 m2D) 934 m2Ans. AIf path is within the garden then use this formula:2 * B * (L + B – 2 * B)2 * 25 (112 + 78 – 2 * 25)= 5 * 185 = 925 m2  

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AGES SET-9

1. A person’s present age is two-fifth of the age of his mother. After 8 years, he will be one-half of the  age of his mother. How old is the mother at present ?A) 40 yearsB) 41 yrsC) 42 yrsD) 43 yrsAns. ALet the mother’s present age be x years.Then, the person’s present age = 2 x years.5   2 x + 8 = 1 (x + 8)5 2   2(2x + 40) = 5(x + 8)  x = 40 2.The age of father 10 years ago was thrice the age of his son. Ten years hence, father’s age will be twice  that of his son. The ratio of their present ages is :A) 7 : 3B) 13 : 4C) 9 : 2D) 5 : 2Ans. ALet the ages of father and son 10 years ago be 3x and x years respectively.Then, (3x + 10) + 10 = 2[(x + 10) + 10]  3x + 20 = 2x + 40  x = 20.  Required ratio = (3x + 10) : (x + 10) = 70 : 30 = 7 : 3 3. Father is aged three times more than his son Ronit. After 8 years, he would be two and a half times of  Ronit’s age. After further 8 years, how many times would he be of Ronit’s age ?A) 2 timesB) 3 timesC) 4 timesD) 5 timesAns. ALet Ronit’s present age be x years. Then, father’s present age =(x + 3x) years = 4x years.  (4x + 8) = 5 (x + 8)2   8x + 16 = 5x + 40  3x = 24  x = 8. Hence, required ratio = (4x + 16) = 48 = 2.(x + 16) 24 4. A person’s present age is two-fifth of the age of his mother. After 8 years, he will be one-half of the age of his mother. How old is the mother at presentA) 38B) 40C) 42D) 44Ans. BLet the mother’s present age be x years.Then, the person’s present age = (2/5 x) years. => (2/5 x + 8/2) = 1 (x + 8) => 2(2x + 40) = 5(x + 8) => x = 40 5. The sum of the present ages of a father and his son is 60 years. Six years ago, father’s age was five times the age of the son. After 6 years, son’s age will beA) 15 yearsB) 18 yearsC) 20 yearsD) 22 yearsAns. CHINT:(60 – x) – 6 = 5(x – 6)                      

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AGES SET-8

  1. The average weight of A, B and C is 45 kg. If the average weight of A and B be 40 kg and that of B and C be 43 kg, then the weight of B is :A) 31 kgB) 21 kgC) 35 kgD) 30 kgAns. ALet A, B, C represent their respective weights. Then, we have:A + B + C = (45 x 3) = 135 …. (i)A + B = (40 x 2) = 80 …. (ii)B + C = (43 x 2) = 86 ….(iii)Adding (ii) and (iii), we get: A + 2B + C = 166 …. (iv)Subtracting (i) from (iv), we get : B = 312. A pupil’s marks were wrongly entered as 83 instead of 63. Due to that the average marks for the class got increased by half (1/2). The number of pupils in the class is :A) 40B) 41C) 42D) 43Ans. ALet there be x pupils in the class.Total increase in marks = x x 1 = x2 2    x = (83 – 63)    x = 20       x= 40.2 2 3. The captain of a cricket team of 11 members is 26 years old and the wicket keeper is 3 years older. If the ages of these two are excluded, the average age of the remaining players is one year less than the average age of the whole team. What is the average age of the team ?A) 21 yrsB) 22 yrsC) 23yrsD) 24 yrsAns. CLet the average age of the whole team by x years.  11x – (26 + 29) = 9(x -1)  11x – 9x = 46  2x = 46  x = 23.So, average age of the team is 23 years 4. The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is :A) 50 yrsB) 35 yrsC) 45 yrsD) 40 yrsAns. DSum of the present ages of husband, wife and child = (27 x 3 + 3 x 3) years = 90 years.Sum of the present ages of wife and child = (20 x 2 + 5 x 2) years = 50 years.  Husband’s present age = (90 – 50) years = 40 years 5. The present ages of three persons in proportions 4 : 7 : 9. Eight years ago, the sum of their ages was 56. Find their present ages (in years) :A) 20, 35, 45B) 16, 28, 36C) 8, 20, 28D) None of the aboveAns. BLet their present ages be 4x, 7x and 9x years respectively.Then, (4x – 8) + (7x – 8) + (9x – 8) = 56  20x = 80  x = 4.  Their present ages are 4x = 16 years, 7x = 28 years and 9x = 36 years respectively            

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AGES SET-7

1. Average age of A and B is 24 years and average age of B, C and D is 22 years. The sum of the ages of A, B, C and D isA) 90B) 98C) 120D) Data is not adequateAns. D 2. Total of the ages of A, B ahd C at present is 90 years. Ten years ago, the ratio of their ages was 1: 2: 3. What is the age of B at presentA) 25B) 30C) 45D) 60Ans. BLet their ages 10 years ago is x, 2x and 3x years. 10 + 2x + 10 + 3x + 10 = 90 hence x= 10 B?s present age = (2x + 10) =30 years 3. A man is 24 years older than his son. In two years, his age will be twice the age of his son. The present age of his son isA) 20 yearsB) 21 yearsC) 22 yearsD) 24 yearsAns. CLet the son’s present age be x years. Then, man’s present age = (x + 24) years=> (x + 24) + 2 = 2(x + 2)=> x + 26 = 2x + 4So, x = 22 4. A man is 24 years older than his son. In two years, his age will be twice the age of his son. The present age of this son isA) 21 yearsB) 22 yearsC) 23 yearsD) 24 yearsAns. BLet’s Son age is x, then Father age is x+24.=> 2(x+2) = (x+24+2)=> 2x+4 = x+26=> x = 22 years 5. Tanya’s grandfather was 8 times older to her 16 years ago. He would be 3 times of her age 8 years from now. What was ratio of ages of Tanya and her grandfather 8 years ago.A) 11:50B) 11:51C) 11:53D) 11:54Ans. CLet, Tanya age 16 years ago = x, Grandfather’s age 16 years ago = 8x. 8 years from now, 3(x+16+8) = (8x+16+8)=> x = 48/5 8 years ago ratio was: =>x+88x+8=485+88×485+8=>x+88x+8=485+88×485+8=>x+88x+8=485+88×485+8   =>88424=1153=>88424=1153=>88424=1153    

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AGES SET-6

1. Sachin was twice as old as Ajay 10 years back. How old is Ajay today if Sachin will be 40 years old 10 years henceA) 18B) 25C) 15D) 20Ans. DSachin’s age today = 30 years. Sachin’s age 10 years back = 20 years. Ajay’s age 10 years back = 10 years. Ajay’s age today =20 years 2. In 10 years, A will be twice as old5as B was 10 years ago. If A is now 9 years older than B, the present age of B isA) 35B) 37C) 39D) 41Ans. CLet B’s age = x years. Then, As age = (x+ 9) years. (x+9+10)=2(x?10) hence x=39. Present age of B = 39 years 3. Ten years ago A was half of B in age. If the ratio of their present ages is 3 : 4, what will be the total of their present agesA) 30B) 35C) 37D) 41Ans. BLet A’s age 10 years ago = x years. Then, B’s age 10 years ago = 2x years.(x + 10) / (2x+ lO) = 3/4 => x = 5.So, the total of their present ages =(x + 10 + 2x + 10) = (3x + 20) = 35 years. 4. Sushil was thrice as old as Snehal 6 years back. Sushil will be times as old as Snehal 6 years hence. How old is Snehal todayA) 12B) 16C) 18D) 24Ans. ALet Snehals age 6 years back = x. Then, Sushils age 6 years back = 3x. (5/3) * (X + 6 + 6) = (3X + 6 + 6) So 5(x+ 12) = 3(3x+ 12),so x=6. Snehal Age = (x+ 6) years = 12 years 5. Six years ago, the ratio of the ages of Kunal and Sagar was 6:5, Four years hence, the ratio of their ages will be 11:10. What is Sagar age at presentA) 10 yearsB) 12 yearsC) 14 yearsD) 16 yearsAns. DLet six years ago the age of Kunal and Sagar are 6x and 5x resp.then, =>(6x+6)+4(5x+6)+4=1110=>(6x+6)+4(5x+6)+4=1110=>(6x+6)+4(5x+6)+4=1110 <=>10(6x+10)=11(5x+10)<=>10(6x+10)=11(5x+10)<=>10(6x+10)=11(5x+10) <=>5x=10=>x=2<=>5x=10=>x=2<=>5x=10=>x=2 So Sagar age is (5x+6) = 16      

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AGES SET-5

1. Ten years ago, P was half of Q in age. If the ratio of their present ages is 3:4, what will be the total of their present agesA) 35B) 34C) 45D) 25Ans. ALet the present age of P and Q be 3x and 4x respectively.Ten years ago, P was half of Q in age=> 2(3x ? 10) = (4x ? 10) => 6x ? 20 = 4x ? 10 => 2x = 10 => x = 5 2. The total age of A and B is 12 years more than the total age of B and C. C is how many year younger than AA) 11B) 12C) 13D) 14Ans. BGiven that A+B = 12 + B + C=> A ? C = 12 + B ? B = 12=> C is younger than A by 12 years 3. The ages of two persons differ by 16 years. 6 years ago, the elder one was 3 times as old as the younger one. What are their present ages of the elder personA) 15B) 20C) 25D) 30Ans. DLet’s take the present age of the elder person = x and the present age of the younger person = x ? 16(x ? 6) = 3 (x-16-6)=> x ? 6 = 3x ? 66=> 2x = 60=> x = 60/2 = 30 4. The ages of two persons differ by 20 years. If 5 years ago, the elder one be 5 times as old as the younger one, their present ages (in years) are respectivelyA) 20,20B) 20,10C) 25,15D) 30,10Ans. DLet their ages be x and (x + 20) years. 5 (x – 5) = (x + 20 – 5) or 4x = 40 or x = 10. Their present ages are 30 years and 10 years5. Ratio between Rahul and Deepak is 4:3, After 6 Years Rahul age will be 26 years. What is Deepak present age.A) 14B) 15C) 20D) 22Ans. BPresent age is 4x and 3x,=> 4x + 6 = 26 => x = 5 So Deepak age is = 3(5) = 15      

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AGES SET-4

1. Raju age after 15 years will be 5 times his age 5 years back, What is the present age of RajuA) 15B) 14C) 10D) 8Ans. CExplanation:Clearly,x+15 = 5(x-5) <=> 4x = 40 => x = 10 2. Sachin is younger than Rahul by 7 years. If the ratio of their ages is 7:9, find the age of SachinA) 23.5B) 24.5C) 12.5D) 14.5Ans. BIf Rahul age is x, then Sachin age is x-7,so (x-7)/x = 7/9=> 9x-63 = 7x => 2x = 63=> x = 31.5 So Sachin age is 31.5 – 7 = 24.5 3. The ratio between the present ages of P and Q is 6:7. If Q is 4 years old than P, what will be the ratio of the ages of P and Q after 4 yearsA) 7:8B) 7:9C) 3:8D) 5:8Ans. ALet P age and Q age is 6x years and 7x years.Then 7x – 6x = 4 <=> x = 4 So required ratio will be (6x+4): (7x+4) => 28:32 => 7:8 4. Ages of two persons differ by 16 years. If 6 year ago, the elder one be 3 times as old the younger one, find their present ageA) 12,28B) 14,30C) 16,32D) 18,34Ans. BLet the age of younger person is x,Then elder person age is (x+16)=> 3(x-6) = (x+16-6) [6 years before]=> 3x-18 = x+10=> x = 14.So other person age is x + 16 = 30 5. The sum of the ages of a father and son is 45 years. Five years ago, the product of their ages was four times the fathers age at that time. The present age of father and sonA) 34,11B) 35,10C) 36,9D) 40,5Ans. CLet sons age = x years. Then fathers age = (45 – x)years. (x?5)(45?x?5) = 4(45- x – 5) hence (x?5) = 4 so x = 9 Their ages are 36 years and 9 years.    

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AGES SET-3

Q.1 Total age of some 7 years old & some 5 years old children is 60 yrs. If a team is to be selected from these children such that their total age is 48 years, in how many ways can it be done ? A) 2 B) 3C) 4D) 1Ans. D7*4+5*4=28+20=48 Q.2 At present ages of a father & his son are in the ratio of 7:3 & they will be in the ratio of 2 : 1 after 10 years. Then the present age of father is : A) 77 B) 56 C) 70 D) 42 Ans. C Shortcut:Father’s age = x*t (a-b)/ difference of cross productOr x =7t=10a=2b=1therefore,7*10(2-1)/1=70 Q.3 The present ages of A and B are in the ratio 2 : 3 and the ages of A and C are in the ratio 3 : 4. If the sum of the present ages of A, B and C is 92 years, how many years will it take by B and C to get their ages in the ratio 10 : 9? A) 2 B) 4 C) 5 D) 6 Ans. B A : B = 2 : 3 = 6 : 9 (Note: In this since A is common that’s why we have multiplied “2 with 3” & “3 with 9”) A : C = 3 : 4 = 6 : 8 (Multiplied “3 with 2” & “4 with 2”) ? A : B : C = 6 : 9 : 8 ? A age = × 92 = 24 yearsB age = × 92 = 36 years C = × 92 = 32 years After x years, = ? x = 4 years Q.4 The sum of ages of a son & father is 56 years. After 4 years, the age of father will be three times that of the son. Their ages respectively are A) 12 & 44 yrs B) 16 & 42 yrs C) 16 & 48 yrs D) 18 & 36 yrs Ans. A Shortcut:Son’s age=S1+t2(N-1)/N+1 [When age is in years ago] But in this question use this formula because [It is given after years] Son’s age= S1-t2(N-1)/N+1 Therefore,Son’s age is 56-4*2/4=12 where N= 3 as it is given three times Now, for father’s age= It is given in Question ,the sum of ages of a son & father is 56 years Then,12 + father’s age = 56 Father’s age = 56-12= 44 Other explanation: Suppose the age of father be a yrsThen the age of the son = (56-a)After four yrs the age of the father would be (a+4) yrs & the age of the son would (56-a+4)Now (a+4) = 3(56-a+4)(a+4) = 180 – 3aa = 44 yrsSo, the age of father = 44 yrs& the age of son = 56-44= 12 yrs Q.5 The average age of three girls is 16 years. If their ages are in the ratio 4 : 5 : 7, the age of the youngest girl is : A) 21 B) 15 C) 16 D) 12 Ans. CLet the ages of three girls be 4x, 5x, 7x (ratio 4 : 5 : 7 is given)Average age of the three girls = 16 yearsAverage age = = 1616x = 16 3x = 3.Age of the youngest girl = 4x = 4 3 = 12 years. Q.6 The ratio of the ages of two persons (A and B) is 2 : 3 and that of (B and C) is 4 : 5. If the average age of all the three is 35 years. What is B’s age? A) 24 B) 36 C) 40 D) 30 Ans. B Total age of A + B + C = 35 × 3 = 105= ? A = = ? C = ? + B + = 105? B = 36 years.    

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PERCENTAGE & RATIO PROPORTION SET12

Q.1 A cloth merchant has announced 25% rebate in prices. If one needs to have a rebate of $40, how many shirts costing $32 each should he purchase? A) 2 B) 5 C) 10 D) 18 Ans. B C.P. of one shirt = $32 Rebate on one shirt = 0.25 × 32 = $8 To get a rebate of $40, number of shirts to be bought = = 5 Q.2 750 candidates appeared in an examination. 70% of the girls and 65% of the boys passed the examination. If total pass percentage was 67%, find the number of boys that appeared in the examination. A) 400 B) 430 C) 440 D) 450 Ans. D Apply the Rule of Alligation- 70 65 67 2 3 Thus, ratio is: 2:3 Since we have to find boys, then = 3/5 * 750 = 450 Q.3 An employer reduces the number of employees by th and increases their wages by th. What is the ratio of the total wages paid to the employees before the hike and after that? A) 10.0 : 11 B) 11.0 : 10 C) 10.5 : 10 D) 10.5 : 12 Ans. C Let the initial number of employees = n New number of employees = n Let initial wages = x New wages = x ? Ratio of total wages before and after the change = (nx) : = 21 : 20 = 10.5 : 10 Q.4 Aman’s salary is 25% higher than that of Balraj’s. By how much percent is Balraj’s salary lower than that of Aman’s? A)25% B)20% C)15% D)10% Ans. B Let Balraj’s salary be Rs.100 Aman’s salary will be Rs.125 A – B = 125 – 100 = 25 B’s salary is ( ) 100 = 20% Q.5 If the price of sugar goes up by 10%, what should be the percentage reduction in the quantity consumed so that the total expenditure on sugar remains the same? A) 10 % B) 9 % C) 8 % D) 7 % Ans. B Percentage reduction in quantity consumed = × 100 = × 100 = % = 9 % Q.6 In Lok Sabha elections there are two candidates-A & B contesting from North delhi seat. 3/5th of the people promise to vote for A, & the rest promise to vote for B. If 10% of the people who promised to vote for A did not vote & 20% of the people who promised to vote for B did not vote. If B got 6400 votes, how much was the margin of victory for A ? A) 5500 B) 8800 C) 4400 D) 4000 Ans. C Let total votes be X, It is given 3/5th of people =i.e. 3/5*100=60% (Here we have considered people be 100) Now, 10% of the people who promised to vote for A did not vote Then, People voted for A= 60% of x-10% of 60% of x = 0.54 x People voted for B= 40% of x – 20 % of 40 % of x = 0.32 x Now find margin victory for A= i.e. 0.54-0.32= 0.22 x Then, acc to question If B got 6400 votes 0.32x (calculated value of B)= 6400 X= 20000 how much was the margin of victory for A ? i.e. 0.22 (Calculated value of A)=0.22*20000=4400 Votes Q.7 Out of 54600 candidates for an examination, 35% failed to pass while 15% passed with honours. Find the number of candidates who passed the examination but failed to obtain honours. A) 43680 B) 35990 C) 27300 D) None of these Ans. C Total Candidates = 54600 %age of the candidates who failed to pass and who passed with honours (35% + 15%) = 50% %age of candidates who passed but failed to obtain honours. (100 – 50%) = 50% 50 % of 54600 = 27300

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PERCENTAGE & RATIO PROPORTION SET11

Q.1 In a group of 15 students 7 read French, 8 read English, while 3 of them read none of these two. How many of them read French & English both? A) 0 B) 3 C) 4 D) 5 Ans. B Let circles A & B represent people who read French & English respectively X = Students who read French Y = Students who read French & English both Z = Students who read English ( X + Y + Z) + 3= 15 So, (X + Y + Z) = 15-3 =12 (X+Y) = 7 (Y+Z) = 8 Thus, (X+2Y+Z) =15 Subtracting 1 from 2 Y=15-12 =3 Directions: A publishing firm publishes newspaper A, B & C. In an attempt to persuade advertisers to insert advertisements in these newspapers, the firm sends out the following statements to possible advertisers: A survey of representative sample of the whole population shows that: Newspaper A is read by 26% Newspaper B is read by 25% Newspaper C is read by 14% Newspaper A + B are read by 11% Newspaper B + C are read by 10% Newspaper A + C are read by 9% Newspaper C only is read by 00% Q.2 The %age of readers who read all three newspapers is: A) 1 B) 4 C) 5 D) 6 Ans. C %age of readers who read all three newspapers is represented by U = = 5% Q.3 The %age of readers who read A & B but not C A) 2 B) 4 C) 5 D) 6 Ans. D %age of readers who read (A+B) but not C is represented by S = =6% Q.4 The %age of readers who read atleast one of the three newspapers is A) 40 B) 50 C) 60 D) 65 Ans. A The %age of readers who read atleast one of the three newspapers is represented by P+Q+R+S+T+U+V = 11+9+0+6+4+5+5 = 40% EXPLANATION: Suppose the no. of persons= 100 On the basis of information: (P+S+U+T) = 26…….(i) (S+Q+U+V) = 25……(ii) (T+U+V+R) = 14……(iii) (S+U) = 11…..(iv) (U+V) = 10……(v) (T+U) =09…….(vi) R =00…….(vii) From eq. (iii),(vi) & (vii) (T+U+V+R) = 14 9+V+0 = 14 V = 5 U = 5 From eq.(iii) we have T+U+V+R = 14 T+5+5+0 = 14 T = 4 From (iv) we have S =6 From (ii), we have Q+6+5+5 = 25 Q = 9 P= 11 Q= 9 R= 0 S= 6 T= 4 U= 5 V= 5 Q.5 A student divided a number by 2/3 when he required to multiply by 3/2. Calculate the percentage of error in his result. A) 1 % B) 2 % C) 0 % D) 4 % Ans. C Explanation: Since 3x / 2 = x / (2 / 3)

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