Saturday, September 8, 2012

P3 numbers (prep for Olympiad for kids in China)

Grandpa Li is 70 years old and has three grandsons aged five, 15 and 20. How many years does it take before the total of their ages is the same as their grandfather's age?
(This maths question is aimed at Primary 3 pupils in China - or at least those who go for classes to prepare for the International Mathematical Olympiad contest.)
Click here for my solution