Question

The third term of a $G.P.$ is $4$. The product of first five terms is

• A. $4^3$
• B. $4^5$
• C. $4^4$
• D. None of these.

Answer 1

Answer: (B)

$4^5$

Let the $G.P$. be $a+ar+{ar}^2+{ar}^3+.......$
Then as given
$T_3={ar}^2=4.$
$\therefore T_1{T}_2{T}_3{T}_4{T}_5=a.ar.{ar}^2.{ar}^3.{ar}^4=a^5.r^{10}={\left({ar}^2\right)}^5=4^5,$