Suppose that a new fuel-efficient European car travels an average of 28 kilometers on 1 liter of gasoline. If gasoline costs 1.50 euros per liter, how much will it cost to drive 220 kilometers ?
step 1
using proportion
Find out the number of liters of gasoline needed for 220 kilometers
so
step 2
Find the cost to drive 220 kilometers
Multiply the cost of one liter of gasoline by the total liters of gasoline needed to travel 220 Km
So, if the first person takes half of the pizza, half of the pizza is left. If the second person takes half of the amount the first person took, that would be a quarter of the pizza left.