Due to a fall in the rate of interest from $13\%$ p.a. to $12\frac{1}{2}\%$ p.a., a money lender's yearly income diminishes by ₹ $104$. His capital is :
Rate reduce from $13\%$ to $12\frac{1}{2}\% $ p.a.
Decrease in rate $= 0.5\%$
Decline in interest $= \text₹~104$
$\begin{align} 0.5\%~of~capital &= 104 \\ \implies capital &= \frac{104}{0.5}\times 100 = \text₹~20800 \end{align}$
Option B.
Answer is B
$\frac{P*13*1}{100}-\frac{P*25*1}{2*100} = 104$
P = 200*104 = Rs.20800