8. Sequences and Series
medium

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

A

$Rs.$ $245$

B

$Rs.$ $245$

C

$Rs.$ $245$

D

$Rs.$ $245$

Solution

The first installment of the load is $Rs.$ $100 .$

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

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

The $A.P.$ is $100,105,110 \ldots$

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 $30^{\text {th }}$ installment is $Rs.$ $245 .$

Standard 11
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.