Question

If third term of $G.P$ is $2$ then product of its second and fourth terms is

• A. $4$
• B. $16$
• C. $32$
• D. $64$

Answer 1

The correct option is A $4$

Let $a$ be the first term and $r$ be the common difference.

Then according to the problem, $a{r}^2=2$.....(1).

Now, the product of second and fourth term is

$ar.a{r}^3$

$=(a{r}^2{)}^2$

$=2^2$ [ Using (1)]

$=4$.