Chapter 8.1, Problem 47HP

To determine

Write a real world example that uses an equation containing a decimal and a fraction. Then find the solution.

Answer to Problem 47HP

The rental car can be driven 496 miles.

Explanation of Solution

Given:

Write a real world example that uses an equation containing a decimal and a fraction. Then find the solution.

Concept Used:

Fractions are used in baking to tell how much of an ingredient to use. Fractions are used in telling time; each minute is a fraction of the hour. Finally, fractions are used to determine discounts when there's a sale going on.

Calculation:

Example:

If a rental car costs $ $\frac{2}{5}$ plus 10 cents per mile driven, how many miles can be driven for $50?

Translating this into an equation gives $20+0.1m=50$ where m is the number of miles driven.

The equation: $\frac{2}{5}+0.1m=50$

Multiply both sides by 5 gives: $5·(\frac{2}{5}+0.1m)=5·50\Rightarrow 2+0.5m=250$

Subtracting 2 on both sides gives: $2-2+0.5m=250-2\Rightarrow 0.5m=248$

Dividing both sides by 0.5 gives: $\frac{0.5m}{0.5}=\frac{248}{0.5}\Rightarrow m=496$

Since m was the number of miles of driven, the solution to the equation is interpreted as 496 miles can be driven.

Thus, the rental car can be driven 496 miles.