Which term of the AP 3, 8, 13, 18, ... is 88?

Question

Philoid · Accepted Answer

In the given AP, the first term = a = 3

Common difference = d = 8 - 3 = 5

To find: place of the term 88.

So, let a_n = 88

Since, we know that

a_n = a + (n - 1) × d

∴ 88 = 3 + (n - 1) × 5

⇒ 88 - 3 = 5n - 5

⇒ 85 = 5n - 5

⇒ 85 + 5 = 5n

⇒ 5n = 90

⇒ n = 90/5

⇒ n = 18

∴ 18^th term of the AP is 88.