Chapter 7.3, Problem 18PPS

To determine

To solve: the given problem by using the percent proportion

Answer to Problem 18PPS

The required answer is 12.

Explanation of Solution

Given:

80% of what number is 12?

Calculation:

Let n represent the number.

  $\begin{array}{l}\frac{\text{12}}{\text{n}}\text{=}\frac{\text{80}}{\text{100}}\text{ Write the percent proportion}\\ \text{12×100=n×80 Find the cross product}\\ \text{1200=80n Multiply}\\ \frac{\text{1200}}{\text{80}}\text{=}\frac{\text{80n}}{\text{80}}\text{ Divide each side by 80}\\ \text{15=n Simplify}\end{array}$

So, 80% of 15 is 12.

Conclusion:

Hence, 80% of 15 is 12.