Find the probability that one ball is white when two balls are drawn at random from a basket that contains 9 red, 7 white and 4 black balls.

A 18/95

B 18/190

C 1/2

D 91/190

Correct Answer: Option D

Total number of elementary events = $20C_2$ ways =190

There are 7 white balls out of which one white can be drawn in ⁷ C₁ways and one ball from remaining 13 balls can be drawn in $13C_1$ ways

So,favourable events = $7C_1\times13C_1$

Therfore,required probability = $\frac{7C_1\times13C_1}{20C_2}$ = 91/90

$13 C_{1}$