Question

Joan needed $100 to buy a graphing calculator for her math class. Her neighbor will pay her $5 per hour to baby sit and her father gave her $10 for mowing the lawn. What is the minimum number of hours she has to baby sit in order to pay for her calculator? Write and solve the inequality.

Answer 1

Joan needs to babysit for at least 18 hours to pay for her calculator.

Step-by-step explanation:

To determine the minimum number of hours Joan needs to babysit in order to pay for her calculator, we need to set up an inequality.

Let's say she babysits for x hours.

Joan will earn $5 per hour for babysitting, so the amount of money she earns from babysitting is 5x.

In addition, her father gave her $10, so her total earnings become 5x + 10.

To find the minimum number of hours she needs to babysit, we need to set up an inequality:

5x + 10 ≥ 100

Now, we can solve the inequality:

5x + 10 ≥ 100

Subtract 10 from both sides: 5x ≥ 90

Divide both sides by 5: x ≥ 18

Therefore, Joan needs to babysit for at least 18 hours to pay for her calculator.