Re: Gokhale Sample Paper Doubts

Posted by Nag27 on Jun 08, 2013; 6:51am
URL: http://discussion-forum.276.s1.nabble.com/Gokhale-Sample-Paper-Doubts-tp7581861p7581981.html

Q No. 6: Answer is option (D).

1) From (2a-6b)^8, first take out 2^8 so you get (a-3b)^8.
2) By the Pascal Triangle you get the 4th term's coefficient as 56.
3) b's exponent in the term will be 3, so 3^3 is also multiplied to the coefficient.

As a result, you will see that the coefficient is (2^8)*(3^3)*(56) which (with some arithmetic manipulation) is nothing but option (D)