Hi Im taking senior maths challenge this year and was looking over some of the past paper questions. I did the first 10 questions and they seemed okay (although i took a bit of time on the year question which turned out to be monday) and looked at q10. http://www.wpr3.co.uk/UKMT/smc.html (scroll to q10) Is there any method to tackle this kind of question? I could spend a lot of time experimenting with different numbers but I'm usually used to having some kind of method to go through the question. Any help on a good logical approach/method would be appreciated. Thanks.