Arun
Last Activity: 6 Years ago
Dear student
it means
43 C 2r = 43 Cr+1
43! / 2r! (43-2r)! = 43! / (r+1)! (43- r)!
now solve this. But as calculation may lead to unnecessary time wate.
So try to solve these questions with options checking.
as (a) if r = 14
then 2r = 28
r+ 1 = 15
also here 43C2r = 43Cr+1 as 28 + 15 = 43
hence option A is correct
