Sequence And Series Question 578
Question: If the first term of a G.P. be 5 and common ratio be $ -5 $ , then which term is 3125
Options:
A) $ 6^{th} $
B) $ 5^{th} $
C) $ 7^{th} $
D) $ 8^{th} $
Show Answer
Answer:
Correct Answer: B
Solution:
Given that first term $ a=5 $ and common ratio $ r=-5 $ . Suppose that $ n^{th} $ term is 3125, then $ a{r^{n-1}}=3125\Rightarrow 5{{(-5)}^{n-1}}=3125\Rightarrow {{(-5)}^{n-1}}=5^{4} $ Hence $ \Rightarrow $ .
BETA
