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What is the smallest perfect square that ends with the four digits 9009?


Find the positive integer solutions of the equation (1+1/a)(1+1/b)(1+1/c) = 2

Instant Insanity

Given the nets of 4 cubes with the faces coloured in 4 colours, build a tower so that on each vertical wall no colour is repeated, that is all 4 colours appear.

Twin Equivalent Sudoku

Age 16 to 18 Challenge Level:

Twin A

Solution grid A

Twin B

Solution grid B