Question

a person pays rs 975 in monthly installments suxh that each is less than earlier i stallment by rs 5 . if first installment is rs 100 then in what time will tge entire amoubt be paid

Answer 1

make an ap (arithmetic progression)

with a =100, d = -5 and Sn=975

u get equation n^2 -41n +390=0

on solving thiswe get ans as 15

thus in 15 installment it would be paid