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# Big Blackboard

The whole numbers from 1 to 2016 are written on a blackboard.

Moritz underlinesĀ all the multiples of two in red, all the multiples of three in blue, and all the multiples of four inĀ green.

How many numbers does Moritz underline exactly twice?

This problem is taken from the UKMT Mathematical Challenges.## You may also like

### Consecutive Numbers

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The whole numbers from 1 to 2016 are written on a blackboard.

Moritz underlinesĀ all the multiples of two in red, all the multiples of three in blue, and all the multiples of four inĀ green.

How many numbers does Moritz underline exactly twice?

This problem is taken from the UKMT Mathematical Challenges.

You can find more short problems, arranged by curriculum topic, in our short problems collection.

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.