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

Explanation

The first installment of the loan is Rs. 100.

The second installment of the loan is Rs. 105 and so on.

The amount that the man repays every month forms an A.P.

The A.P is 100,105,110,..
.
First term, a=100, common difference d=5

`a_30​=a+(30−1)d=100+(29)(5)=100+145=245`

Thus, the amount to be paid in the 30th installment is Rs. 245.