Question

In your top dresser drawer are 6 blue socks and 10 grey socks, unpaired and mixed up. one dark morning you pull two socks from the drawer (without replacement, of course!). what is the probability that the two socks match?

Answer 1

We'll use the formula for the classical probability as follows.

P(A) = Number of outcomes favorable for A / Total number of possible outcomes

In this case, two socks are randomly drawn from a set of 6+10 = 16 socks. So the total number of possible outcomes = 16C2 = 120.

The two stocks match each other if they are both blue or grey. So the number of favorable outcomes is 6C2 + 10C2 = 15 + 45 = 60.

Hence the probability that the two stocks match is $\frac{60}{120}=0.5$.