How many terms are there in the AP 41, 38, 35, ..., 8?

Question

Philoid · Accepted Answer

In the given AP, the first term = a =41

Common difference = d = 38 - 41 = - 3

Last term = 8

To find: No. of terms in the AP.

Since, we know that

a_n = a + (n - 1) × d

∴ 8 = 41 + (n - 1) × (-3)

⇒ 8 - 41 = - 3n + 3

⇒ - 33 = - 3n + 3

⇒ - 33 - 3 = - 3n

⇒ - 3n = - 36

⇒ n = 36/3

⇒ n = 12

∴ Number of terms = 12.