Stefan takes out two socks at random.

Work out the probability that Stefan takes out two socks of the same colour

Need more information to answer this question. How many socks total? How many colours? How many socks of each colour?

You need to know how many socks there are in total. if they are all back socks, then there is a definite probability that stefan with take out two socks of the same colour. but if there is one sock of each colour, there is a lower probability that he will take out the same colour sock.