Percentage — CDS Elementary Mathematics PYQs

What is the least number of complete years in which a sum of money put out at 20% compound interest (compounded annually) will be more than doubled?

100 quintals is what percent of 10 metric tonnes?

How much will ₹ 10,000 amount to in one year's time at 4% rate of interest per annum if the interest is compounded once in every three months? (take approximate value)

There are two employees $X$ and $Y$. $X$'s salary is first increased by 12% and then decreased by 10%, and $Y$'s salary is first increased by 10% and then decreased by 12%. If their salaries at present are equal, then what was the ratio of initial salary of $X$ to initial salary of $Y$?

In a village consisting of $p$ persons, $x$% can read and write. Of the males, only $y$% can read and write. Of the females, only $z$% can read and write. If $x,y>z$, then what is the number of males in the village?

A Question is given followed by two Statements I and II. Consider the Question and the Statements.

Question:
If the price of petrol goes up by 20%, by what percentage should the consumption be reduced so that the expenditure remains the same?

Statement-I: Price of petrol per litre was Rs. 90

Statement-II: Consumption was 24 litre before price hike

Which one of the following is correct in respect of the above Question and the Statements?

What is the square root of 64%?

If the length of a rectangle is increased by $66\frac{2}{3}$, then by what percent should the width of the rectangle be decreased in order to maintain the same area?

$X$ sells his goods 25% cheaper than $Y$ and 25% dearer than $Z$. How much percentage is $Z$'s goods cheaper than $Y$?

In a mixture of 80 litres of a liquid and water, 25% of the mixture is the liquid. How much water should be added to the mixture so that the liquid becomes 20% of the mixture?