Question

Your drawer contains five red socks and eight green socks. its too dark to see which are which. What is the probability that the first two you pick are both red socks?

Answer 1

`20/169`

Explanation:

The drawer contains `5+8 = 13` socks. There are therefore `5` chances out of `13` that the first sock is red.

This would leave `4` red socks in a drawer still holding`12` socks. The probability of the next sock being red is therefore `4` out of `12`.

The probability of both events occurring is the product of the two probabilities. i.e. `(5/13)*(4/12) = 20/169`