Question

For the G.P., if a = `2/3`, t₆ = 162, find r.

Answer 1

Given, a = `2/3,` t₆ = 162

t_n = ar^n–1

∴ t₆ = `2/3"r"^(6 - 1)`

∴ 162 = `2/3"r"^5`

∴ r⁵ = `162 xx 3/2`

∴ r⁵ = 3⁵

∴ r = 3.