Chapter 3, Problem 28CR

To determine

To find: the number of hours you must work to earn at least $200.

Answer to Problem 28CR

At least $27.6$ hours

Explanation of Solution

Given:

The amount paid per hour for baby-sitting = $7.25

Concept Used:

Let a, b and c be real numbers where $c>0$ . Then,

If $a\ge b$ , then $\frac{a}{c}\ge \frac{b}{c}$

Let you need to work for x hours to earn at least $200.

Since, the hourly pay for baby-sitting is $7.25, so amount earned after x hours is $\$7.25x$ .

Now, this amount is greater than or equal to $200. So, it can be written in inequality form as:

  $7.25x\ge 200$

Now to solve this inequality, divide both sides of the given inequality by 7.25,

  $\frac{7.25x}{7.25}\ge \frac{200}{7.25}$

Simplify both sides of the inequality,

  $x\ge 27.6$

Conclusion:

Hence, is can be said that to earn at least $200 you must work for at least 27.6 hours.