WBCS Mains 2021 (Held On May 2022) Official Paper-VI

A sum of money at compound interest amounts to $\text{Rs. }650$ at the end of the first year and $\text{Rs. }676$ at the end of the second year. The sum of money is:

Entomology : Insect :: Ornithology : ?

How much time will it take for an amount of $\text{Rs. }450$ to yield $\text{Rs. }81$ as interest at $4.5\%$ per annum of simple interest?

If the length of a rectangle is increased by $30\%$ and width by $20\%$, its area will be increased by: