Given: Fifth term of GP is 2

⇒ Let the first term be a and the common ratio be r.

∴ According to the question,

T₅ = 2

We know,

a_n = ar^n-1

a₅ = a.r^5-1

2 = ar⁴

GP = a,ar,ar²,…,ar⁸

Product required = a×ar×ar²×…×ar⁸

= a⁹.r³⁶

= (ar⁴)⁹

= (2)⁹

= 512