Question

a quarter of a gallon of gasoline can be used to travel 20 miles. how far can one travel with a whole gallon?

Explanation:

Step1: Understand the ratio

A quarter gallon ($\frac{1}{4}$ gallon) gives 20 miles. We need to find miles per 1 gallon.

Step2: Set up the proportion

Let $x$ be miles for 1 gallon. The ratio of gallons to miles should be constant: $\frac{\frac{1}{4}}{20}=\frac{1}{x}$. Cross - multiply: $\frac{1}{4}x = 20\times1$.

Step3: Solve for x

Multiply both sides by 4: $x=20\times4 = 80$.

Answer:

80 miles