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Plum Tree

Label this plum tree graph to make it totally magic!

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Magic W

Find all the ways of placing the numbers 1 to 9 on a W shape, with 3 numbers on each leg, so that each set of 3 numbers has the same total.

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2-digit Square

A 2-Digit number is squared. When this 2-digit number is reversed and squared, the difference between the squares is also a square. What is the 2-digit number?

Triangles Within Triangles

Age 14 to 16 Challenge Level:
It is usefult to be able to recreate these patterns on square dotty paper.
Is the way the triangles fit together always going to work with two consecutive triangular numbers?

Yuu might find it useful to look at the problem on "Sequences and Series".