Question

A person borrows Rs 4500 and promises to pay back(without interest) in 30 installments, each of value Rs 10 more than last . Find First and last. (AP)

Answer 1

Given is sum of 30 installments is 4500. so total terms is 30 and sum of 30 terms is 4500.
and common differnece d is 10.
d=10
applying formula
S30=30/2(2a+(30-1)10)
by solving we get a=5.
so ap will be like this
5,15,25....
now 30 term will be
a+29d
5+29*10=295
so first installment is 5 and last is 295.

Answer 2

Answer:

Given is sum of 30 installment is 4500.

so total terms is 30 and sum of 30 terms is 4500

and common difference d is 10

d=10

applying formula

s30 = 30/2{2a+(30-1)10}

by solving we get a=5

so ap will be like this 5,15,25....

now 30 terms will be

a+29d

5+29×d

5+29×10=295

so first installment is 5 and last installment is 295