There are 30 pens in a box.
12 of the pens are black. 7 of the pens are green. The rest of the pens are red.
One of the pens is chosen at random.
Find the probability that the pen is red.
Practise CIE IGCSE Maths Probability with exam-style questions for Core and Extended tier. 28 questions, matched to the CIE IGCSE Maths (0580) specification and written in Paper 1 and Paper 3 (Core) or Paper 2 and Paper 4 (Extended) 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.