Chapter 6, Problem 19CR

To determine

To find the number students got $A$ grade.

Answer to Problem 19CR

  $28$

Explanation of Solution

Given:

The percent problem “what is $76\%$ of $38$ ?”.

Concept used:

To translate a phrase of the form “whatis $A$ percent of $B$ ?” to an equation. First, assume that the numberis $x$ . Then, read the statement is $A\%$ of In “ $A\%$ of the word “of” represents “multiplication”. So, the given statement can be translated in to an equation as follows:

  $\begin{array}{ccccc}x& \text{is}& A\%& \text{of}& B\\ \downarrow & \downarrow & \downarrow & \downarrow & \downarrow \\ x& =& \frac{A}{100}& ·& B\end{array}$

So, the equation becomes $x=\frac{A}{100}·B$ .

Calculation:

Using the concept, the given statement can be translated into an equation as

  $x=76\cdot \frac{1}{100}\cdot 38$ .

Now, solve the equation as follows:

  $\begin{array}{c}x=76\cdot \frac{1}{100}\cdot 38\\ x=28\end{array}$

Therefore, number of students who got $A$ grade is

  $x=28$

Conclusion:

The solution of the percent problem is $28$ .