In the expansion of (1+x)30 , the sum of the coefficients of odd powers of x is
230
231
0
229
We have, (1+x)30=1+C1 30x+C2 30x2+C3 30x3+…+C29 30x29+C30 30x30 Therefore, sum of coefficient of odd powers of x is C1 30+C3 30+….+C29 30=230-1=229