WBCS Mains 2019 Official Paper-VI

There is $25\%$ profit if an article is sold at Rs. $150$. At what per cent should the selling price be increased so that there will be $30\%$ profit?

A sum of money doubles itself in $8$ years at some rate of simple interest. In how many years would it triple itself?

A sum of amounts will be doubled in $7\frac{1}{2}$ years. What is the rate per cent?

A sum amounts to Rs. $1180$ in $3$ years and to Rs. $1300$ in $5$ years. Find the rate of interest.

A certain sum amounts to Rs. $17,200$ at $12\%$ simple interest per annum in a period in which Rs. $22,080$ amounts to Rs. $37,536$ at $14\%$ simple interest per annum. Find the sum.