Question

0.29. Which term of the AP 21, 18, 15, ... , is zero?​

Answer 1

Answer:

The given Arithmetic Progression is 21, 18, 15,…,0,….

The first term = a = 21

Now the common difference = d = -3

nth term = 0

We need to find n.

nth term = a + (n-1)d

0 = 21 + (n-1)(-3)

⇒ 3(n-1) = 21

⇒ n-1 = 7

⇒ n = 8

⇒ The 8th of the given Arithmetic Progression is 0.