TO BE frank, we weren't surprised no one took up our challenge to answer the sum we set you earlier in the week.

It was one of the calculations Kent student Alison Zhu answered correctly to become the first girl to top score in the qualifying competition for the British Mathematical Olympiad.

Let us remind you of the question:

Find the minimum value of x squared + y squared + z squared where x, y, z are real numbers such that x tripled + y tripled + z tripled minus 3xyz = 1.Got that? Perhaps not quite as easy as pi but all in a day's calculations for Alison, an 18-year-old A-level student at Simon Langton Girls’ Grammar School, Canterbury.

She is now in training for this year’s International Mathematical Olympiad in Madrid this July and hopes to be selected for the British team for a second time.

If you think the question looks tough then do find a moments to look at the answer. It will blow your mind - unless, like Alison, you're off to Trinity College, Cambridge, to read mathematics.

~ See the answer here >>>