Question

What are the possible numbers of hours.Use t for the number of hours.An inequality solved for t.

Answer 1

The cost of renting a room has two terms:

1) A fixed cost of $18.

2) An additional fee of $6 per hour.

Then, if t is the number of hours, we can write the cost as:

$C(t)=18+6t$

Then, if the maximum cost is $90 for this group, we can find the maximum number of hours as:

$\begin{gathered} C(t)\le90 \\ 18+6t\le90 \\ 6t\le90-18 \\ 6t\le72 \\ t\le\frac{72}{6} \\ t\le12 \end{gathered}$

The number of hours has to be equal to or less than 12.

Answer: t ≤ 12