Question

How many digits will be there after decimal point in $12^{th}$ term of the sequence : $32$ , $16$ , $8$ , $4$ ,...... ?

• A. $5$
• B. $6$
• C. $7$
• D. $8$

Answer 1

Answer: (B)

We have $32,16,8,\mathrm{4....}$ are in $G.P.$
$a=32,r=\frac{1}{2}$
Then, $12^{th}$ term of the sequence $=a{r}^{12-1}$
$=32\times \frac{1}{2^{11}}=2^5\times 2^{-11}=2^{-6}$
$=0.015625$
Hence, six digits will be there after decimal point in $12^{th}$ term of the sequence.