The number of terms in the expansion of (x + a)¹⁰⁰ + (x $$-$$ a)¹⁰⁰ after simplification is

In the expansion of (1 + x)⁵⁰, the sum of the coefficients of odd powers of x is

The value of [C(7, 0) + C(7, 1)] + [C(7, 1) + C(7, 2)] + ..... + [C(7, 6) + C(7, 7)] is

The expansions of (x $$-$$ y)ⁿ, n $$\ge$$ 5 is done in the descending powers of x. If the sum of the fifth and sixth terms is zero, then $${x \over y}$$ is equal to