Question

A car agency charges $\$ 15$ a day plus $\$ 0.12$ per mile for its rental cars. If these charges include tax, what is the total cost of travelling 400 miles in 3 days in a car rented from this agency?
A. $\$ 45$
B. $\$ 48$
C. $\$ 93$
D. $\$ 144$
E. $\$ 189$

Answer 1

Hint: In the solution, since per day charge is given, so first we have to find the charge for three days by multiplying the per day charge with 3. After that we have to calculate the charge for 400 miles by multiplying the 400 miles with the charge per mile. Finally, we have to add them both. This will give the total charge for the travelling.

Complete step by step solution:
It is given that the charge for one day is $\$ 15$ and the charge per mile is$\$ 0.12$.
Now, calculating the charge for 3 days.
Charge for three days
                                         $\begin{array}{l} = \$ 15 \times 3\\ = \$ 45\end{array}$

Similarly, calculating the charge for 400 miles.
Charge for 400 miles is
                                           $\begin{array}{l} = \$ 0.12 \times 400\\ = \$ 48\end{array}$

Now, we have to add both the charges to get the total charge for travelling 400 miles in 3 days.
Therefore, the total cost is
                                                 $\begin{array}{l} = \$ 45 + \$ 48\\ = \$ 93\end{array}$

Hence, the total cost for travelling 400 miles in 3 days is $\$ 93$.

Note: In this problem, we use a unitary method to find the answer. Unitary method is a technique, where the information for the single unit is known and by multiplying it with the number of required units, we get the values of the multiple units. Here we have to determine the total charge for travelling 400 miles in 3 days. Since the cost per day and charge per mile are given, thus we can easily calculate the required total cost using a unitary method.