Question

At what rate of interest per annum, the simple interest on a certain sum becomes 2/5 times of amount in 10 years of simple interest?​

Answer 1

$\huge \mathtt\red{ \to\: ANSWER}$

$\frac{ptr}{100} 52 \: p \\ or \frac{10 \times r}{100} = \frac{2}{5} \\or \: r = \frac{20}{5} </p><p> = 4\%$

Hence,4% is the answer