The 17th term of an AP exceeds its 10th term by 21. The common difference of the AP is

Question

Philoid · Accepted Answer

|

Let a be the first term and d be the common difference.

Given: a₁₇ = a₁₀ + 21

To find: common difference = d

Consider a₁₇ = a₁₀ + 21

⇒ a + 16d = a + 9d + 21

⇒ 16d = 9d + 21

⇒ 16d - 9d = 21

⇒ 7d = 21

⇒ d = 3

∴ Common difference = 3