# Percentage- Aptitude Questions and Answers

 Due to an increase in the price of eggs by 30%, now 3 less eggs are available for Rs.9.10. The present rate per egg is? A) 91 paise B) 70 paise C) 48 paise D) 84 paise Correct Answer :91 paise Explanation :Let the original price of a egg= X New price, 30% increased in the price => (1+30/100)X =>13X/10 according to question 9.10( 1/X - 1/(13X/10) )=3 (9.10/3)(3/13)=X X=9.1/13 So present price of a egg i.e. new price=>13X/10 =>(13/10)(9.1/13) =>.91 44% of the students in the class are females and the number of male students is 42. Find the total number of students in the class? A) 70 B) 65 C) 75 D) 45 Correct Answer :75 Explanation :% of females student =44 So % of male students=(100-44)=>56 Let the total number of students=X then 56% of X <=> 56X/100=42 X=4200/56 Therefore total students = X => 75 The price of petrol falls down by 20%. By how much percent must a man increase his consumption, so as to keep his expenditure constant? A) 42% B) 25% C) 20% D) 10% Correct Answer :25% Explanation :Let initial price of petrol =Rs. 100 per ltr Initial monthly consumption =100 ltr Total monthly expenditure =100×100=Rs. 10000 New price of petrol(falls down by 20%)=Rs. 80 per ltr Let new monthly consumption=x ltr New monthly expenditure =80*x to keep monthly expenditure remain constant⇒ 10000=80*x ⇒x=125 i.e., increase in consumption=25% The height of a tree is 800cm and it increases 10% yearly. Find the height of the tree after three years? A) 1000 cm B) 1060.4 cm C) 1052.6 cm D) 1064.8 cm Correct Answer :1064.8 cm Explanation :The height of a tree after n yeras , if it increases at the rate of R% per annum= P [1+(R/100)]n Thus, The height of the tree after three years= 800 [1+(10/100)]3 => 800 [11/10]3 => .8*11*11*11 => 1064.8 cm The price of an apple is increased from Rs.50 per kg to Rs.75 per kg. By what percent a person shall need to decrease his consumption in order to have the same expenditure? A) 20% B) 25% C) 16(2/3)% D) 33(1/3)% Correct Answer :33(1/3)% Explanation :Let original consumption = 100 kg and new consumption = x kg, So, 100*50 = x*75 x=200/3 Reduction in consumption (100-200/3)= 100/3 = 33(1/3)% In an examination a candidate who got 30% of the total marks failed by 8 marks. Another candidate who got 35% marks scored 12 marks more than the passing marks. Total marks are? A) 500 B) 400 C) 800 D) 300 Correct Answer :400 Explanation :Let x be the maximum marks, Then (30% of x)+8 = (35% of x)-12 3*x/10 + 8 = 7*x/20 - 12 3*x + 80 = (7*x - 240)/2 6*x + 160 = 7*x -240 Hence,Minimum marks x=400 The salary of a worker is first increased by 30% and afterwards reduced by 30%. What is the net change in his salary? A) 91% increase B) 30% decrease C) 9% decrease D) None of these Correct Answer :9% decrease Explanation :Let a original number is = 100 New number, increased by 30% = 100 + (30% of 100) = 130 Now it is reduced by 30% = 130 - (30% of 130) = 91 that means , in net it is 100 - 91 = 9% decreasing Or If something increased by x% and reduced by x% then net effect will be loss of (x/10)2 % = (30/10)2 = 9 % A boy, after giving away 80% of his pocket money to one companion and 6% of the remainder to another, has 94 paise left with him. How much pocket money did the boy have in the beginning(in rupees)? A) 2 B) 2.5 C) 5 D) 10 Correct Answer :5 Explanation :Let the boy had Rs.x Money given to his companion = 80% of x = 4x/5 Remaining money = x - 4x/5 = x/5 Money given to another companion = (6/100)*(x/5) = 3x/250 Remaining money => x/5 - 3x/250 = 94/100 (in rupees) so 47x/250 = 94/100 x = 94*250/100*47 x = 5 (in rupees) If the price of petrol is increased by 25%, by what percent the consumption of petrol must be reduced so that expenditure remains unchanged? A) 20% B) 25% C) 33% D) 50% Correct Answer :20% Explanation :Let initial price of petrol =Rs. 100 per ltr Initial monthly consumption =100 ltr Total monthly expenditure =100×100=Rs. 10000 New price of petrol(increased by 25%)=Rs. 125 per ltr Let new monthly consumption=x ltr New monthly expenditure =125*x to keep monthly expenditure remain constant⇒ 10000=125*x ⇒x=80 i.e., reducedtion in consumption=20% If the price of sugar is decreased by 25%, by what percent the consumption of sugar must be increase so that expenditure remains unchanged? A) 20% B) 25% C) 33(1/3)% D) 50% Correct Answer :33(1/3)% Explanation :Let initial price of Sugar=Rs. 100 per kg Initial monthly consumption =100 kg Total monthly expenditure =100×100=Rs. 10000 New price of Sugar(falls down by 25%)=Rs. 75 per kg Let new monthly consumption=x kg New monthly expenditure =75*x to keep monthly expenditure remain constant⇒ 10000=75*x ⇒x=133(1/3) i.e., increase in consumption=33(1/3)% The first class ticket price of a circus is 12. When the price is decreased then the number of visitors increased by 80% and the total income is increased by 20%. Now, what is the price of each ticket? A) 8 B) 10 C) 6 D) 15 Correct Answer :8 Explanation :Let 100 was the visitors. On the ticket price 12 the total collection = 12 *100 = 1200 After decreased in price , let it be X. New visitors= 100 + 80% of 100 =>180 New income, total income after 20% increased = 1200 + 20% of 1200=>1440 Therefore, New collection = X * 180 = 1440 => X = 1440/180 thus, Price of each ticket ,X = 8 If M% of x is y and N% of y is x, then ? A) M+N = 100 B) MN = 10000 C) M/N= 100 D) N/M = 100 Correct Answer :MN = 10000 Explanation :Y is M percent of X --> (MX/100)=Y X is N percent of Y --> (NY/100)=X Thus, after subsitute Y's value =>(N/100)*(M/100)*X=X =>MN=10000 Out of the total production of iron from hematite, an ore of iron, 20% of the ore gets wasted, and out of the remaining iron, only 25% is pure iron. If the pure iron obtained in a year from a mine of hematite was 80,000 kg, then the quantity of hematite mined from that mine in the year is? A) 500000 kg B) 400000 kg C) 450000 kg D) 550000 kg Correct Answer :400000 kg Explanation :Let 100 kg of hematite be obtained then 20% of it get wasted that means 80 kg of ore remains. Pure iron = 25% of remaining ore = 80*25/100 = 20 kg. 20 kg pure Iron is obtained from 100 of hematite. 1 kg pure Iron is obtained from = 100/20 hematite; Then, 80000 kg pure Iron is obtained from = (100/20)*80000 = 400000 kg hematite. The total population of a country is 294000, out of which 150000 are males. Out of every 100 males, 98 can read and write, but only 53% of the total population can do so. Find the percentage of women who can read and write? A) 6.125 % B) 5.125 % C) 6.000 % D) 4.125 % Correct Answer :6.125 % Explanation :Number of men who can read and write = 150000 × (98 ÷ 100) =147000 Number of men and women who can read and write =294000 × (53 ÷ 100) =155820 Number of women who can read and write 155820 - 147000 = 8820 Thus, out of 144000 women 8820 can read and write. Required percentage = (8820 × 100) ⁄ 144000 %= 6.125 68% of a number is 280 more than 43% of the same number. Find the number? A) 1120 B) 1210 C) 1200 D) 1800 Correct Answer :1120 Explanation :The difference in percentage = 68% - 43% = 25% i.e. 25% of a number = 280 therefore, the number = 280 × 100 / 25 => 1120 The population of a town is 100000. If it increases at the rate of 5% per annum, what will be the population of the town after 2 years? A) 11000 B) 110000 C) 110250 D) 11025 Correct Answer :110250 Explanation :If the present population of the town is P now and it increases at the rate of R% per annum, then: Population after n yeras = P [1+(R/100)]n The population after 2 years= 100000 [1+(5/100)]2 = 100000*21/20*21/20 = 110250