There are 10 counters in a bag. 5 of the counters are red. 3 of the counters are blue. 2 of the counters are green. Billie takes two counters are taken at random from the bag.
Work out the probability that both of the counters Billie takes are the same colour.
You must show your working.
Practise OCR GCSE Maths Conditional Probability with exam-style questions for Foundation and Higher tier. 28 questions, matched to the OCR GCSE Maths (J560) specification and written in the written papers style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.