Question

The first three terms of an A.P. respectively are 3y – 1, 3y + 5 and 5y + 1. Then, y equals 

A. –3 

B. 4 

C. 5 

D. 2

Answer 1

A.P here is 3y – 1, 3y + 5 and 5y + 1. 

So d= common difference = a₂– a₁= a₃–a₂ 

3y + 5 – (3y–1) 

= (5y + 1) – (3y + 5) 6 

= 2y – 4 10 / 2 = y

y = 5