Question

The first three terms of an AP are respectively (3y – 1), (3y + 5) and (5y + 1), find the value of y .

Answer 1

The terms (3y -1), (3y +5)  and (5y +1) are in AP.

∴ (3 y + 5) - (3y-1) = (5y+1) - (3y+5)

⇒ 3y + 5-3y +1 = 5y + 1-3y-5

⇒6 = 2y-4

⇒ 2y = 10

⇒ y = 5 

Hence, the value of y is 5.