Chapter 4.1, Problem 62STP

a.

To determine

Expression for total cost of car rental

Answer to Problem 62STP

  $45·d·c$

Explanation of Solution

Given information:

Cost for one car rental for one day $=\$45$

Number of cars $=c$

Number of days $=d$

Calculation:

Cost of renting one car for $d$ days $=45·d$

Cost of renting $c$ cars for $d$ days $=45·d·c$

b.

To determine

Expression for total cost of car rental

Answer to Problem 62STP

  $35dc$

Explanation of Solution

Given information:

Cost for one car rental for one day(till seven days) $=\$45$

Cost for one car rental for one day(more than seven days) $=\$45-\$10$

Number of cars $=c$

Number of days $=d$

Calculation:

Cost of renting one car for $d$ days $\left(d>7\right)$

  $=\left(45-10\right)d$

Cost of renting $c$ cars for $d$ days $\left(d>7\right)$

  $=\left(45-10\right)d·c=35dc$

c.

To determine

Cost for four and nine days

Answer to Problem 62STP

  $\$140$ and $\$315$

Explanation of Solution

Given information:

Four and nine days

Calculation:

Cost for car rental for seven days or less $=45·d·c$

Cost for car rental for more than seven days $=35·d·c$

Cost for renting one car for four days $=45·4·1=\$140$

Cost for renting one car for four days $=35·9·1=\$315$

d.

To determine

Number of days a car can be rented

Answer to Problem 62STP

  $9\text{days}$

Explanation of Solution

Given information:

Available money= $\$300$

  $c=1$

Calculation:

Cost for car rental for more than seven days $=35·d·c$

Cost for renting one car for more than seven days $=35·d·1=35·d$

  $\begin{array}{l}35·d=300\\ \Rightarrow d=\frac{300}{35}=8.6\approx 9\text{days}\end{array}$