Question

What is the total cost for fixing a drain that takes 6 hours?If the plumber charged a total of 364$ how many hours did she spend fixing the drain?

Answer 1

a) Recall that to evaluate a function at a given value, we substitute the variable by the given value.

Therefore, evaluating C(h) at h=6 we get:

`C(6)=76+24\cdot6.`

Simplifying the above result we get:

`\begin{gathered} C(6)=76+144 \\ =220. \end{gathered}`

b) Setting C(h)=364 we get:

`76+24h=364.`

Subtracting 76 from the above equation we get:

`\begin{gathered} 76+24h-76=364-76, \\ 24h=288. \end{gathered}`

Dividing the above equation by 24 we get:

`\begin{gathered} (24h)/(24)=(288)/(24), \\ h=12. \end{gathered}`

Answer:

(a) $220.

(b) 12.