A bag contains \[\mathbf{3}\] white, \[\mathbf{5}\] black and \[\mathbf{2}\] red balls, all of the same shape and size. A ball is drawn from the bag without looking into it, find the probability that the ball drawn is: \[\left( \mathbf{iii} \right)\] a white ball. \[\left( \mathbf{iv} \right)\] not a red ball.

Solution

\[\left( iii \right)\]There are \[3\] white balls

So, the number of favourable outcomes \[=\text{ }3\]

Thus, P(getting a white ball) \[=~3/10\text{ }=\text{ }3/10\]

\[\left( iv \right)\])There are \[3\text{ }+\text{ }5\text{ }=\text{ }8\] balls which are not red

So, the number of favourable outcomes \[=\text{ }8\]

Thus, P(getting a white ball) \[=~8/10\text{ }=\text{ }4/5\]