Question

A series of book was published at seven year intervals. When the seventh book was published the total sum of publication year was 13,524. First book was published in?

Answer 1

Answer:

the years at which books are published are terms of AP where

let first term a be x;

common difference (d) =7

number of terms(n)=7

sum of seven terms(S7)=13524

n/2[2a+(n-1)d]=13524

7/2[2x+6(7)]=13524

2x+6(7)=3864

x=1911

therefore the first book was published in 1911