Mammoth Memory

Finding the original number

 

Example 1

A car is sold for `£360` after a discount of `20%`. Find the original price.

Guide to show how to find the original number

NOTE:

`£360` after a discount of `20%` is the same as saying `£360` is `80%` of the original price.

Guide to show how to find the original number pt2

Multiply both sides by `360` to get `x` on its own (remember – what ever you do to one side you do to the other).

  `(100times360)/80=(xtimescancel360)/cancel360`

  `(100times360)/80=x`

`x=(100timescancel360\ \ \ 4)/cancel80`

`x=100times4=400`

 

Answer: The original price is `£400`

  

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