Brain Teasers and Puzzles

A box for your workings out:

Hint: Start with the cube root of 1,287.

Answer: 9, 11 and 13.

Since we're after three numbers that multiply together, a good place to start is the cube root of 1,287, which is 10.88 (2 dp).

We quickly find that the numbers must be 9, 11 and 13.