Mammoth Memory

Direct proportion versus inverse proportion

There are two proportions

Direct is to divide inverse means to multiply



Proportion or direct proportion example

Apples are directly proportional to money

 `8` apples cost `£4.00`

and so `24` apples cost `£12.00`


Inverse proportion example

The length of time to paint a room is inversely proportional to the number of people painting it.

`3` people take `8` hours

`4` people take `6` hours (i.e. less than `8` hours)

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