how long will it take the car to pass the​ truck?

Question

A truck enters a highway driving 60 mph. A car enters the highway at the same place 10 minutes later and drives 65 mph in the same direction. From the time the car enters the highway, how long will it take the car to pass the truck

Answer 1

Okay let's say the time the truck travels is 'x'. 

Since the car arrives on the freeway 10 minutes after the truck, it will be represented by the expression 'x-10' (truck's time - 10 minutes). 

We are looking to see how many minutes it will take for the car to catch up to the truck; therefore, we have to make the expressions equal to each other.

Attach the mph to the according variables, and you will come up with this:

 

60x = 65(x-10)

 

Then, solve for x.

 

60x = 65x-650

-5x = -650

x = 130

x = the truck's time, so x-10 (the car's time) is 120.

 

Therefore, it will take 120 minutes or 2 hours for the car to pass the truck.