Writing Inequalities

Question

Suppose that you go into business doing plumbing repairs. You decide to charge $25 per hour, plus a fixed fee of $30 for the service call. How many hours would be work for your customer to pay at least $100?

Answer 1

You start with $100 (total cost) - $30 (fixed fee) = $70, because you don't want the fixed fee mixed into the hourly rate, you subtract the fixed fee from the total cost first

Then to find the number of hours, you divide $70 by $25 (which = 2.8) because $25 is the hourly rate and $70 is the total amount of money left that the customer has to spend

Therefore, $100 - $30 = $70 / $25 = 2.8 (hours of work)

So, for exactly $100 total cost paid by the customer, you would need to work for 2.8 hours