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Question 1
If 3% of A + B = 11% of A - B, then what percent of B is A?
$1{3/4}$ %.
$3{2/3}$ %.
${1/2}$ %.
$3{1/6}$ %.
Ans: a
We have been given 3% of A + B = 11% of A - B, so ${A + B}/{A - B}$ = $11/3$. By componendo and dividendo, ${(A + B) + (A - B)}/{(A + B) - (A - B)}$ = ${11 + 3}/{11 - 3}$, which gives $A/B$ = $14/8$ = ${7/4}$, which is same as: $1{3/4}$%
Question 2
The age of Mr. X is 80% more than Mr. Y's age which is 20 years at present. By what percent is Y's age less than Mr. X's age?
$44{4/9}$ %.
$51{1/8}$ %.
$35{6/11}$ %.
$38{9/11}$ %.
Ans: a
Age of Mr. X is 20 + ${80 × 20}/100$ = 36 years. Mr. Y's age is less than Mr. X's age by ${80 × 20}/100$ = 16 years. In terms of percentage, it is $16/36$ × 100 = ${400/9}$, which is same as: $44{4/9}$.
Question 3
The age of Mr. X is 40% more than Mr. Y's age which is 20 years at present. By what percent is Y's age less than Mr. X's age?
$28{4/7}$ %.
$34{1/2}$ %.
$21{4/9}$ %.
$24{5/9}$ %.
Ans: a
Age of Mr. X is 20 + ${40 × 20}/100$ = 28 years. Mr. Y's age is less than Mr. X's age by ${40 × 20}/100$ = 8 years. In terms of percentage, it is $8/28$ × 100 = ${200/7}$, which is same as: $28{4/7}$.
Question 4
The service tax is 5%. A person receives a telephone bill amounting to Rs. 840. How much was the bill excluding tax?
Question 5
A number is first increased by 20%, and thereafter it is reduced by 20% again. What is the overall reduction?
4 %.
6 %.
10 %.
8 %.
Ans: a
Let us derive the shortcut formula first, so that you can remember it and use it when the need arises. Suppose the number is 100, and let the increase be x%. The number becomes 100 + x. When it is reduced by x%, we get 100 + x - $((100 + x) × x)/100$ = 100 + x - $(x + x^2/100)$ = 100 - $x^2/100$, hence a reduction of $x^2/100$ = 4%
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This Blog Post/Article "Percentages Quiz Set 004" by Parveen (Hoven) is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Updated on 2020-02-07. Published on: 2016-05-12