Answer please

Question

Two cars travel the same distance. The
old clunker travels at a rate of 40 mph for x
hours. The sedan travels at a rate of 55
mph and reaches its destination 3 hours
earlier than the old clunker. Write and
solve and equation to find out how long it
took both cars to reach their destination?

Answer 1

What do we know?

 

Clunker car: time = x        speed = 40 mph      distance = d

Sedan:         time = x-3     speed = 55 mph      distance = d

 

distance = rate * time, or d = speed * time

 

Set up this equation for both cars:

 

Clunker: d = 40 * x 

Sedan:   d = 55 * (x-3)

 

As you can see, both the clunker and sedan travel the same distance, so we can set the right side of both equations equal to each other:

 

40x = 55(x-3)

 

Now solve:

 

40x = 55x-165

165 = 15x

x = 15 

 

Since x=15, then it took 15 hours for both cars to reach their destination