Chapter 7.5, Problem 32HP

To determine

To check:Ifcalculations done by Todd are correct or done by Jon is correct.

Answer to Problem 32HP

The percent given by Todd is correct.

Explanation of Solution

Given information:

Todd and Jon are trying to find 28 is what percent of 80.

Todd:

  $\begin{array}{l}28=p\cdot 80\\ p=0.35\\ \text{so,}\text{28}\text{is}\text{35\%}\text{of}\text{80}\end{array}$

Jon:

  $\begin{array}{l}p=80\cdot 0.28\\ p=22.4\\ \text{so,}\text{28}\text{is}22.4\text{\%}\text{of}\text{80}\end{array}$

Calculation:

Let the percent of 80 is 28 is p, then

  $\begin{array}{l}p=\frac{28}{80}\\ p=0.35\\ \text{so,}\text{28}\text{is}\text{35\%}\text{of}\text{80}\end{array}$

Hence, the percent given by Todd is correct.

And the percent given by Jon is not correct.

Because the percent of $x\text{is}y=\frac{y}{x}$ .

But Jon gave the percent by multiply

  $\begin{array}{l}p=80\cdot 0.28\\ p=22.4\\ \text{so,}\text{28}\text{is}22.4\text{\%}\text{of}\text{80}\end{array}$

so, Jon is not correct.