Out of 30 consecutive integers, 2 are chosen at random. The probability that their sum is odd, is

Question

Philoid · Accepted Answer

2 integers out of 30 can be chosen in ³⁰C₂ ways.

As in first 30 integers, 15 are even and 15 are odd.

To have the sum of 2 integer odd one integer must be even and other must be odd.

∴ integers can be chosen in ¹⁵C₁ × ¹⁵C₁ ways

∴ Probability =

Our answer matches with option (c)

∴ Option (c) is the only correct choice