10C1 + 10C3 + 10C5 + 10C7 + 10C9 =
None of these
We know that
2n−1 = nC0 + nC2 +nC4 + ..........= nC1 + nC3 + nC5 +........
So, 10C1 + 10C3 + 10C5 + .........+ 10C9 = 210−1 = 29