Copyright © University of Cambridge. All rights reserved.

## 'Inside Outside' printed from http://nrich.maths.org/

**If you can see this message Flash may not be working in your browser**
**Please see http://nrich.maths.org/techhelp/#flash to enable it.**
The bar balances with a weight of 4 units on one side and
weights of 2 units and 3 units on the other.

The 2 is on the inside and the 3 is on the outside.
The 3 weight and the 4 weight are exactly the same distance from
the pivot, and the 2 weight is half way between the 3 weight and
the pivot.

Can you find an arrangement with the 4 staying exactly where it
is, balanced again by the 2 and 3, but this time with the 3 on the
inside and the 2 on the outside?

There is more than one way to do that, so first find at least
two arrangements that work, then try to describe, using algebra,
the connection between the 2 and 3 positions.

You can use the lines in the background to help you gauge
distances when you are looking for the relationship between the
positions of the 2 and 3 unit weights.