Question

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

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

Answer 1

The correct option is B $4^5$

Let the G.P. be $a+ar+a{r}^2+a{r}^3+$........

Then as given
$T_3=a{r}^2=4...\left(1\right)$

$\therefore T_1{T}_2{T}_3{T}_4{T}_5=a.ar.a{r}^2.a{r}^3.a{r}^4=a^5.r^{10}=(a{r}^2{)}^5=4^5,$ by (1)