MCQ
In a G.P., 5th term is 27 and 8th term is 729. Find its 11th term.
- A729
- B2187
- C6561
- ✓19683
✓
Answer
Correct option: D.
19683
- 19683
Given, $a_5 = 27$ and $a_8 = 729$.
$\Rightarrow ar^4 = 27$ and $ar^7 = 729$
On dividing we get, $r^3 = 27 \Rightarrow r=3$
$\Rightarrow\text{a}=\frac{23}{(3^4)}=\frac{1}{3}$
$\Rightarrow\text{a}_{11}=\text{a}^{10}$
$=(\frac{1}{3})(3^{10})=39=19683$
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