You don't multiply liters of gasoline by distance.
They are directly proportional - the more gasoline you have the longer is the dictance you can go.
So it's cross multiply.
Another examlpe:
you are paid by hour for your work. The more hours you have worked, the more you are paid:
hours payment
2 h $36
5 h x

You would multiply 10•70 if they were inversely poportional values
For example:
1. speed and time of ride by given distance {the greater the speed the less time you need for a ride}
speed time
10 m/s 75 s
8 m/s x

2. price and kolos of apples - the higher the pice the less of kilos you can buy by given cash
price kilos of apples
$2 8
$4 x
