mobile mathematics

the guardian point out exactly why we need algebra [*] though anyone who thinks that algebra is about x’s and y’s rather than inclusive minutes and monthly charges shouldn’t be teaching maths to start with.

You are choosing a pay-as-you-go mobile phone. Network X will give you 100 minutes calling time, and Network Y offers 60 minutes. You would like to invite some friends to join you at School Disco.com. Anyone you call on network X will come along, but each person you call on network Y has a 7-2 chance of bringing a friend with pigtails in a school skirt. Assume it takes you 53 seconds to explain the situation and that you use the phone up. On average, is it better to go with network X or Y if you want loads of mates? [*]at least i think that’s the intention, most of the questions only require traditional algebra and most of the rest are just silly.