1) A sum of money becomes $\frac{41}{40}$ of itself in $\frac{1}{4}$ years at certain rate of simple interest. The rate of interest per annum is A) 10% B) 1% C) 2.5% D) 5% E) 12% Answer: Option AExplanation:Let $P=1$, $SI$ $=\frac{41}{40}-1$ $=\frac{1}{40}$ Rate % $=\frac{(100*SI)}{P\times N}$ $=\left(\frac{\frac{1}{40}\times 100}{1\times\frac{1}{4}}\right)$ = 10%
