Team Leader's report from 2016 IMO.
Team Leader's report from 2015 IMO.
The following problems give a flavour of the style of problem considered in the enrichment classes.
x + y = a; z + u = b; v + w = c; ay = bz; ub = cv; wc = ax .
Hamilton Avenue has eight houses. On one side of the street are the houses numbered 1, 3, 5, 7 and directly opposite are houses 2, 4, 6, 8 respectively. An eccentric postman starts deliveries at house 1 and delivers letters to each of the houses, finally returning to house 1 for a cup of tea. Throughout the entire journey he must observe the following rules. The numbers of the houses delivered to must follow an odd-even-odd-even pattern throughout, each house except house 1 is visited exactly once (house 1 is visited twice) and the postman at no time is allowed to cross the road to the house directly opposite. How many different delivery sequences are possible?