Sequence And Series Question 79

Question: If $ a,,b,,c $ are in A.P., then $ (a+2b-c) $ $ (2b+c-a) $ $ (c+a-b) $ equals

[Pb. CET 1999]

Options:

A) $ \frac{1}{2}abc $

B) abc

C) 2 abc

D) 4 abc

Show Answer

Answer:

Correct Answer: D

Solution:

$ (a+2b-c),(2b+c-a),(c+a-b) $ $ =(a+a+c-c)(a+c+c-a)(2b-b) $ $ =4,abc. $ $ (\because a,b,c $ are in A.P.,
$ \therefore 2b=a+c) $ .