Sequence And Series Question 276
Question: If $ a,\ b,\ c $ , d are any four consecutive coefficients of any expanded binomial, then $ \frac{a+b}{a},\ \frac{b+c}{b},\ \frac{c+d}{c} $ are in
Options:
A) A.P.
B) G.P.
C) H.P.
D) None of the above
Show Answer
Answer:
Correct Answer: C
Solution:
Let $ a={}^{n}{C_{r-1}},\ b={}^{n}C_{r},,C={}^{n}{c_{r+1}} $ and $ d={}^{n}{c_{r+2}} $ . Substituting these values in problem, we get $ \frac{a+b}{a},\ \frac{b+c}{b},\ \frac{c+d}{c} $ are in H.P.