Question

A jar has 3 yellow, 5 blue and 3 green marbles. What is the probability of choosing…

1) 2 blue

2) 1 blue and 1 yellow

3) 3 green

Answer 1

Solution

Total marbles in the jar = 3 + 5 + 3 = 11

1) total number of blue marbles in the jar = 5

2 blue marble out of 5 can be chosen in = 10 ways

2 marble out of total 11 can be chosen in ways

So probability of choosing 2 blue marbles= 10/55 = 0.1818

2) 1 blue marble out of 5 can be choosen in ways

1 yellow marble out of 3 can be chosen in

These 2 marbles (1 blue , 1 yellow) out of 11 can be chosen in ways

So probability of choosing 1 blue and 1 yellow= (5*3)/55= 0.2727

3) . 3 green marble out of 3 can be chosen in ways

3 marbles out of 11 can be chosen in 165 ways

So probability of selecting 3 marbles = 1/165 = 0.006