There are n n\,n counters in a bag.
4 of the counters are red and the rest are blue.
Ross takes a counter from the bag at random and does not replace it. He then takes another counter at random from the bag.
The probability that Ross takes two blue counters is 13\displaystyle \frac{1}{3}31
Show that n2−13n+30=0n^2 - 13n + 30 = 0n2−13n+30=0
Find the value of nnn.
Practise CIE IGCSE Maths Probability Equation Questions with exam-style questions for Core and Extended tier. 7 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.
