The Singing Hedgehog Guide to:
Ratio and Proportion 6

           
Here is a harder example:

A car travels 20km for each litre of petrol.
If one litre costs 1.19, how far will the car travel on 50 of petrol?


We start by cutting out the litres and writing the question as a ratio:

travel  : cost
20km  : 1.19
  :
 :50

Again there is a blank row and we turn 1.19 into one,
then into the target number, 50.

travel  : cost
20km  : 1.19
20/1.19 :1divide by 1.19
50x20/1.19
= 840km
 :50times by 50

So the answer is 840km.
next page

return to SHG main page