Question

12 marbles are in a bag; 3 each of red, blue, green, and orange. If 3 marbles are chosen at random, what is the probability that all 3 are green?

Answer 1

Answer:
`(1)/(220)`

Explanation:

Given

There are 3 marbles of red, blue, green and orange

Total marbles are 12

No of ways of choosing 3 green marbles out of 3 green marbles is
`^3C_3`

Total no of ways of selecting 3 marbles out of 12 are
`^(12)C_3`

So, the probability is

`\Rightarrow P=(^3C_3)/(^(12)C_3)=(1* 3* 2* 1)/(12* 11* 10)\\\\\Rightarrow P=(1)/(220)`