There are 12 socks in a drawer. 7 of the socks are black. 5 of the socks are white. Two socks are picked at random from the drawer.
Work out the probability that one sock of each colour is picked.
You must show your working.
72 exam-style questions on OCR GCSE Maths Conditional Probability. Each one has a worked solution and a mark scheme showing where the marks go.