###
**If the fifth term of a GP is 81 and first term is 16, what will be the 4th term of the GP?**

A. 36
B. 18
C. 54
D. 24
**Answer: Option C**

## Show Answer

Solution(By Apex Team)

$\begin{aligned}&5^{th}\text{ term of GP }\\
&=ar^{5-1}\\
&=16\times r^4\\
&=81\\
&\text{ Or, }r=\left(\frac{81}{16}\right)^{\frac{1}{4}}=\frac{3}{2}\\
&4^{\text{th }}\text{ term of GP }\\
&=ar^{4-1}\\
&=16\times\left(\frac{3}{2}\right)^3\\
&=54\end{aligned}$

## Related Questions On Progressions

### How many terms are there in 20, 25, 30 . . . . . . 140?

A. 22B. 25

C. 23

D. 24

### Find the first term of an AP whose 8th and 12th terms are respectively 39 and 59.

A. 5B. 6

C. 4

D. 3

### Find the 15th term of the sequence 20, 15, 10 . . .

A. -45B. -55

C. -50

D. 0

### The sum of the first 16 terms of an AP whose first term and third term are 5 and 15 respectively is

A. 600B. 765

C. 640

D. 680