Question

Mark is a water truck driver. He makes $18 an hour. Determine his earnings for a week if he works 52 hours.

Answer 1

We need to determine Mark's earnings for working 52 hours.

We know that he earns $18 an hour. Let's say he earns x for the 52 hours.

So, we have the following proportion:

earning in dollars number of hours he works

18 1

x 52

Thus, cross multiplying the above values, we obtain:

`\begin{gathered} 1\cdot x=52\cdot18 \\ \\ x=936 \end{gathered}`

Notice that we can multiply 52 by 18 as:

`\begin{gathered} 52\cdot18=52\cdot\left(10+10-2\right) \\ \\ 52\cdot18=52\cdot10+52\cdot10-52\cdot2 \\ \\ 52\cdot18=520+520-104 \\ \\ 52\cdot18=1040-104 \\ \\ 52\cdot18=936 \end{gathered}`

Therefore, his earnings for a week are $936.