Which term of the GP.

2, 8, 32, ……. is 512?

First term (a) = 2

Common ratio (r)

n^th term in the GP (a_n) = ar^n-1

512 = 2×4^n-1

256 = 4^n-1

4⁴ = 4^n-1

Equating powers on both sides

n-1 = 4 = 5