Question

A Jar has five red marbles in at 10 blue ones if you randomly pick a marble without replacing it and then select another what is the fractional probability of getting two red?

Answer 1

2/21

Explanation:

We know that there is a jar which has 5 red marbles and 10 blue marbles in it.

We are to find the fractional probability of getting two red marbles if we randomly pick a marble and then without putting it back we pick another one.

P (getting red marble on first time) =
`(5)/(15) =(1)/(3)`

P (getting red marble on second time) =
`(4)/(14) =(2)/(7)`

P (getting two reds) =
`\frac { 1 } { 3 } * \frac { 2 } { 7 } = \frac { 2 } { 2 1 }`