Question

A jar contains 12 white , 24 gray and 14 black marbles a marble is drawn at random find p(not gray)

Answer 1

Notice that the total number of marbles are

`12+24+14=50`

The probability of not grey means it could be white or black

Hence

P(not grey) = P(white or black)

Since there are 12 whites and 14 blacks the the P(white or black) is

`\begin{gathered} P(WorB)=(12)/(50)+(14)/(50) \\ P(WorB)=(26)/(50) \\ P(WorB)=(13)/(25) \end{gathered}`

Therefore the P(not gray) is:

`P(not\text{ gray\rparen=}(13)/(25)`