SOLUTION: A car uses 50 litres of fuel to complete a 400km along a highway. How far will it go if it uses 20 litres?

So the car makes   = 8 km per liter of the fuel.


Using 20 liters, the car will cover  8*20 = 160 kilometers.    ANSWER



     Or, you can write the proportion   = 



and find the unknown distance  x  from it  x =  = 8*20 = 160 kilometers,

getting the same answer.