Question

If the first term of a G.P. is 8 and its common ratio is −2 . The 3^rd term of this G.P. is ______.

Options

• −32

• 2

• 32

• −2

Answer 1

If the first term of a G.P. is 8 and its common ratio is −2 . The 3^rd term of this G.P. is 32.

Explanation:

Given,

First term of G.P. = 8

Common ratio = −2

By formula,

⇒ a_n = ar^{n − 1}

Substituting values we get :

⇒ a₃ = 8 × (−2)^{3 − 1}

⇒ a₃ = 8 × (−2)²

⇒ a₃ = 8 × 4

⇒ a₃ = 32