Question

A series of book was published at 7 year intervals.when the 7th book was issued the sum of publication year is 13524.when was the 1st book published ?

Answer 1

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

Answer 2

Answer:

Step-by-step explanation:

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