Q1 of 42 Page 153

If nC8 = nC2, find nC2.

Given: nC8 = nC2


We know that if nCr = nCp then either r = p or r = n – p


Here nC8 = nC2


⇒ 8 = n – 2


⇒ n = 10


Now,


∴ nC2= 10C2 = (∵ nCr = )


⇒10C2 =


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