UPSC ONLINE ACADEMY

PERCENTAGE & PROPORTION

PERCENTAGE & RATIO PROPORTION SET2

Q.1 In a survey it was found that 40 % like tea,50% like coffee , 60% like milk. Every person likes atleast one of the thrice items tea/coffee/milk. What are the maximum & minimum possible values who like all the three ? A) 25 & 50 B) 50 & 25 C) 30 & 60 D) 60 & 30 Ans. A Maximum value = Surplus/2 Or Surplus = 40+50+60 = 150/3 Surplus=50 Or 50/2=25 Minimum Value = Surplus = 50 Ans. Q.2 In a survey it was found 80% like tea & 70 % like coffee. What is the minimum number of those who like this ? A) 50 B) 60 C) 70 D)80 Ans. A A U B = n A + n B – n(A n B) Or 100 = 80+70-n(A n B) n (A n B) = 150-100 = 50Q.3 In two successive years 104 & 96 students of a school appeared at the final examination & 75% & 87 ½ % passed. The average % of the passing is :- A) 80 % B) 81 % C) 82 % D) 83 % Ans. B % of passing = Total passing / Total students * 100 Students passed in Ist year = 104*75/100 = 78 Students passed in IInd year = 96*87.5/100 = 84 Therefore, total pass = 78+84 = 162 Or Total students = 104+96 = 200 Thus, according to the formula, we have 162/200*100 = 81% Q.4 Salaries of A & B together amount Rs.2000/- A spent 95 % of his salary & B 85% of his salary . If now their savings are same. What is the A’s salary ? A) 1500 B) 750 C) 1250 D) 1800 Ans. A Salary of A & B together Rs. 2000/- Let A’s salary =x then B’s salary = (2000-x) Expenditure of A = 95% of x Savings of A = 5% of A Savings of B=15% of (2000-x) 5% of A = 15% of B Or 5x/100 = 15/100 (2000-x) Or 5x = 30000-15x 20x = 30000 Or x=1500 Q.5 A’s salary is 30% more than the B’s salary. B’s salary is 40 % of C’s salary . If the total salary of A,B & C together is 7680. What is the A’s salary ? A) 2060 B) 2070 C) 2080 D) 2090 Ans. C Let C’s salary be 100, B = 40/100*100 = 40X A = 4      

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PERCENTAGE & RATIO PROPORTION SET1

Q.1 The salary of a worker was first increased by 10% & decreased by the 5%. What was the change in his salary ? A) 4.5 % B) 4.6 % C) 5.5 % D) 5.6 % Ans. A Shortcut: x-y-xy/100 or 10-5-10*5/100 4.5 % Q.2 If population of a town is increased by the 20% in the 1st year & is decreased by the 20% in the next year ,what effect can see in the population ? A) 3 % B) 4 % C) 5 % D) 6 % Ans. B Shortcut : (x)2/100 Or 202/100 Or 400/100 = 4 % Q.3 In an examination 40% of the students failed in Mathematics , 30% failed in the English & 10% failed in both. Find the % of the students who passed in both the subjects ? A) 40 % B) 41 % C) 42 % D) 43 % Ans. A 100- (40+30-10) = 100-(70-10) 100-60 =40% Ans. Q.4 Due to reduction in the price of the apples by 10% a customer can buy 2kg of apples more for Rs. 180. Find the original price of the apples per kg ? A) Rs. 13 B) Rs. 12 C) Rs. 11 D) Rs. 10 Ans. D 10% of 180 = 10/100 * 180 = 18 Therefore, Cost of 2kg of apples = Rs. 18 Cost of 1 kg of apples = Rs. 9 Let reduced price /kg = Rs.9 Let original price /kg = Rs. x Or x-10x / 100 = 9 90x / 100 = 9 X= 10 Q.5 In a library 60% of the books are in Hindi, 50% of remaining are in English & remaining 900 are in other languages . What is the total no. of books are in English ? A) 9000 B) 10000 C) 11000 D) 12000 Ans. A Hindi = 20/100 X English = 50/100*80/100 (i.e. remaining) = 40/100 x Now, total books i.e. 20x/100 + 40x/100+9000 = x On solving ,we get X=22500 Now, to solve no. of books in English, 40/100 * 22500 = 9000    

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