MCQ
In a G.P., 5th term is 27 and 8th term is 729. Find its 11th term.
- A729
- B2187
- C6561
- D19683
✓
Answer
- 19683
Solution:
Given, a5 = 27 and a8 = 729.
⇒ ar4 = 27 and ar7 = 729
On dividing we get, r3 = 27 ⇒ 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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