Question

The radio station manager will award a free stereo to a contest winner. There are 20 black stereos, 15 white stereos, 10 red stereos, and 5 silver stereos to choose from. What is the probability that the stereo randomly selected by the contest winner is NOT white?

Answer 1

Solution:

we are given that

The radio station manager will award a free stereo to a contest winner. There are 20 black stereos, 15 white stereos, 10 red stereos, and 5 silver stereos to choose from.

we have been asked to find

The probability that the stereo randomly selected by the contest winner is NOT white?

Total number of stereo=50

Total number of white stereo=15

1  can nbe chosen out of 50 in ${50}_C_1$ ways.

1  can nbe chosen out of 15 in ${15}_C_1$ ways.

So the probability that the chosen sterio is white $=\frac{ {15}_C_1 }{{50}_C_1} =0.3$

So the probability that the chosen sterio isNOT  white $=1-0.3=0.7$