Question

a sum of ₹6240is paid of in 30 installments,such that each installment is₹10 more than the preceding installment.calculate the value of first installment

Answer 1

S=6240
n=30
d=10
it is an AP
6240=30/2(2a+(30-1)10)
6240/15=2a+290
a=(416-290)/2
=126/2=63 is first installment

Answer 2

Answer:

5950

Step-by-step explanation:

$S_n=6240$

A sum of ₹6240 is paid of in 30 installments,such that each installment is₹10 more than the preceding installment.

So, d = 10

Formula of Sum of first n terms =$S_n=a+(n-1)d$

where a is the first installment or first term and n is the no. of installments

$6240=a+(30-1)10$

$6240=a+(29)10$

$6240=a+290$

$6240-290=a$

$5950=a$

Hence the value of first installment is 5950