Question

A man starts repaying a loan as first instalment of Rs 100 = 00. If he increases the instalments by Rs 5 every month, what amount he will pay in the 30th instalment?

Answer 1

Let $a_{30}$ be the amount a man repays in the 30th instalment.
Let d be the common increment in his instalment every month.
Let a be the initial repayment.
Here, a = 100, d = 5, n = 30
Amount to be repaid in the 30th instalment:
$a_{30}$$\Rightarrow$a+$\left(n-1\right)$d
$$\begin{gathered} =100+29\times 5 \\ =245 \end{gathered}$$

Hence, the man repays Rs 245 in his 30th instalment.