AP EAPCET 20-Aug-2021 Shift 2 Paper

Here, n=11 and subset have atmost 5 elements
∴ Total subset = (Subset with 0 element) + (Subset with 1 element) + (subset with 2 element) + (subset with 3 element) + (subset with 4 element) + (subset with 5 element)
=(‌11C0+‌11C1)+(‌11C2+‌11C3)+(‌11C4+‌11C5)
=‌12C1+‌12C3+‌12C5 [∵‌nCr+‌nCr−1=‌n+1Cr]