Question

How mny terms are there in A.P .1,3,5,...73,75?​

Answer 1

Answer:

Given AP is 1 + 3 + 5 + ... + 73 + 75 Here a = 1, d = 3 − 1 = 2 nth term an = 75 nth term of AP is an = a + (n − 1)d ⇒ 75 = 1 + (n − 1) × 2 ⇒ 74 = (n − 1) × 2 ⇒ 37 = (n − 1) ∴ n = 38 Hence there are 38 terms in the given AP.