Proportions Math Example 4

Follow the full solution, then compare it with the other examples linked below.

Example 4

hard
A car travels 180 km on 15 litres of fuel. How many litres are needed for a 540 km trip?

Solution

  1. 1
    Set up the proportion: 18015=540x\frac{180}{15} = \frac{540}{x}.
  2. 2
    Cross-multiply: 180x=15×540=8100180x = 15 \times 540 = 8100.
  3. 3
    Solve: x=8100180=45x = \frac{8100}{180} = 45.

Answer

45 litres45 \text{ litres}
Real-world proportion problems require matching the same units in corresponding positions of the two ratios.

About Proportions

An equation stating that two ratios are equal, used to find an unknown when three of the four values are known.

Learn more about Proportions →

More Proportions Examples

Example 1 easy

Solve the proportion [formula].

Example 2 medium

If 5 notebooks cost [formula]8.75$, how much do 12 notebooks cost?

Example 3 easy

Solve: [formula].

Example 5 medium

Solve the proportion: [formula].

← All Proportions Examples Proportions Concept