Question

A northbound train and a southbound train meet each other on parallel tracks heading in opposite directions. The northbound train travels 12 miles per hour faster than the southbound train. After 2 hours, they are 240 miles apart. At what speeds are the two trains traveling?

please help me, I'm gonna fail my test tomorrow

Answer 1

Speed of northbound train = 66

Speed of southbound train = 54

Explanation:

First, let's make the variables simpler:

Speed of southbound train = x

Thus:

Speed of northbound train = y = x + 12

Distance = speed · time

240 = 2 ( x + x + 12 ) = 2 ( 2x + 12 ) = 4x + 24

216 = 4x

x = 54

Now, plug in x to find the speed of the northbound train (y):

y = 54 + 12 = 66