BMAT 2008 · Question 3 · Ratio/Proportion/Percentage
SaveJim has all his screws jumbled up in a big jar. The number of screws it contains is as follows:
He needs a 4 mm screw but doesn’t mind whether it is 35 or 45 mm long. If he takes one out at random, what are the chances that it will suit his purpose? (Answer to the nearest 1 %)