There are n n\,n counters in a bag.
5 of the counters are red and the rest are blue.
Sarah takes a counter from the bag at random and does not replace it. She then takes another counter at random from the bag.
The probability that Sarah takes two blue counters is 37\displaystyle \frac{3}{7}73
Show that 2n2−37n+105=02n^2 - 37n + 105 = 02n2−37n+105=0
Find the value of nnn.
Practise OCR GCSE Maths Probability Equation Questions 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.