Question

The distance traveled by a car at a constant rate is proportional to the time spent driving. In the equation d = 45t, d represents the distance (in miles) and t represents the time (in hours).
A. What is the constant of proportionality? _____ miles per hour

B. How far will a car travel in 3 hours? _______ miles

Answer 1

Answer: A. 45 miles per hour

B. 135 miles

Step-by-step explanation:

Given: The distance traveled by a car at a constant rate is proportional to the time spent driving.

In the equation $d=45t$, d represents the distance (in miles) and t represents the time (in hours).

$\Rightarrow\frac{d}{t}=45\text{ miles per hour}$

⇒ The constant of proportionality=45 miles per hour.

Also, the distance traveled by car in 1 hour=45 miles

⇒ The distance traveled by car in 3 hours=$3\times45=135\text{ miles}$

∴ A car will travel 135 hours in 3 hours.

Answer 2

It looks like the car is traveling 45mph so 
A= 45 miles per hour
B: 45x3=135
B=135