Question

A plumber charges a one time visit fee and then charges on hourly basis plus the rate for any part/material needed plus the tax on the required material value. If the total cost of completing a job that takes $h$ hours is given by the function $C\left(h\right)=45h+1.06\left(82.5\right)+75$, then the term $1.06\left(82.5\right)$ represents

• A. the hourly rate
• B. the site visit fee
• C. the cost of the materials, including tax
• D. the cost of the materials, not including tax

Answer 1

Answer: (C)

the cost of the materials, including tax

The total cost consists of the site visit fee $=$ constant

An hourly cost $=$ which depends on the number of hours

The cost of the materials (which are taxed).

The constant in the equation is $75$ and is therefore the site visit fee.

$45$ is being multiplied by $h$ (the number of hours), so $45$ must be the hourly rate. That leaves the remaining term, $1.06\left(82.5\right)$, which must be the cost of the materials $\left(82.50\right)$ plus a $6\%$ tax.