Back to Questions

A man arranges to pay off a debt of Rs 3600 by 40 annual instalments which are in $A.P$. When 30 of the instalments are paid he dies leaving one-third of the debt unpaid. The value of the $8^{th}$ instalment is:


Rs 35


Rs 50


Rs 65


Rs 70

 Hide Ans

Option(C) is correct

Let the first instalment be '$a$' and the common difference between any two consecutive instalments be '$d$'

Using the formula for the sum of an $A.P$.


We have,


\(\Rightarrow 180=2a+39d\)-------- (i)


\(\Rightarrow 160=2a+29d\)-------- (ii)

On solving both the equations we get:

$d=2$ and $a=51$

Value of $8^{th}$ instalment $=51+(8−1)2$ 

Rs 65

(3) Comment(s)


hey hw to find 8t der ny u gt Value of 8th instalment $=51+(8-1)2$

$= \text{Rs. } 65$


$S_8= a+(8-1)d$

Hence $51 + 7 \times 2 = 65$


Yeah Gamer is right.