2015 GCSE O Level Math paper, not so difficult but thousands of Sec. 4 British students complain tough. It is an excellent question combining Probability & Algebra.
The British Math system which Singaporeans inherit at Sec. schools is applied and non-abstract thinking. The fact that it uses abstract ‘n’ (instead of concrete number, say, 10), the students’ brain cannot visualize ‘n’ sweets.
The French Math system, on the opposite, is abstract since Troisième, equivalent to Sec. 3, but not very applied.
It is good to have the best of both worlds: applied and abstract Math from Sec.3 /4.