There are n n\,n counters in a bag.
5 of the counters are red and the rest are blue.
Adam 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 Adam takes two blue counters is 16\displaystyle \frac{1}{6}61
Show that n2−13n+36=0n^2 - 13n + 36 = 0n2−13n+36=0
Find the value of nnn.
Hence, find the probability that Adam takes two red counters.
43 exam-style questions on Eduqas GCSE Maths Probability Equation Questions. Each one has a worked solution and a mark scheme showing where the marks go.