- Home
- Standard 11
- Mathematics
14.Probability
easy
Out of $40$ consecutive natural numbers, two are chosen at random. Probability that the sum of the numbers is odd, is
A
$\frac{{14}}{{29}}$
B
$\frac{{20}}{{39}}$
C
$\frac{1}{2}$
D
None of these
Solution
(b) Required probability $ = \frac{{{}^{20}{C_1} \times {}^{20}{C_1}}}{{{}^{40}{C_2}}} = \frac{{20 \times 20 \times 2}}{{40 \times 39}} = \frac{{20}}{{39}}.$
Standard 11
Mathematics
