Question

If the sum of three consecutive terms in a geometric progression is $21$ and their product is $216$, then which of the following is the middle term of the given geometric progression?

• A. 3
• B. 12
• C. 6
• D. 8

Answer 1

The correct option is C 6

Let the numbers be $\frac{a}{r},a,ar.$

Then, product $=216$

$\Rightarrow \frac{a}{r}.a.ar=216$

$\Rightarrow a^3=216$

$\Rightarrow a=6$
Clearly $a=6$ is the middle term.
Hence, the correct option is C.