Question

Cara earns $3 per hour babysitting. If h represents

the number of hours Cara worked babysitting last
week, which of the following represents the number
of dollars she earned last week?

Answer 1

R = 3h (Where R = revenue)

Explanation:

Let's say Cara worked for 3 hours.
She earns $3 the first hour, then another $3 for the second, and finally $3 for the third.

In total, she earned $3 + $3 + $3 = $3 x 3 = $9.

Let's say Cara worked for 5 hours.
She earns $3 the first hour, $3 the second, $3 the third, $3 the fourth, and finally, $3 the fifth.

In total, she earned $3 + $3 + $3 + $3 + $3 = $3 x 5 = $15.

As you can see by these examples, the amount of money Cara earns for babysitting is directly proportional to the amount of hours she worked.

Since she earns $3 for every hour she works, we can summarize the relationship between Cara's revenue and Cara's work hours per week to be: R = 3 * h, where R is Cara's revenue, and h is Cara's work hours.

We usually don't write the multiplication sign between a constant and a parameter, therefore we'll write the relationship as R = 3h.