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

The sum of the selected numbers is odd, if exactly one of them is even and one is odd.
 Favorable number of cases =  ${ }^{15}{\mathrm{C}}_1{\cdot }^{15}{\mathrm{C}}_1$
Required probability $=\frac{{ }^{15}{\mathrm{C}}_1{\cdot }^{15}{\mathrm{C}}_1}{{ }^{30}{\mathrm{C}}_2}=\frac{15}{29}$