1) Bill can drink a barrel of beer in six days. Bert can drink a barrel of beer in 12 days (assume they’re both really going for it). How long would it take them to drink a barrel together?
2) When it comes to maths, Jane is pretty average. In fact, on a recent test, her mark was both the 15th highest and the 15th lowest in the class. How many students are there in the class?
3) Ernie is a keen eBayer. He buys a rare comic for £60, sells it for £70, buys it back again for £80, then finally sells it for £90. What was his final profit?