What equation will you use?

Question

A train moving 60 mph leaves the station at noon. An hour later, a train moving 80 mph leaves heading the same direction on a parallel track. Find the time when the second train catch up to the first.

What equation will you use? 

What time does the second train catch up to the first one?

Answer 1

60t= 80(t-1)

expand

60t=80t-80

80t-60t=80

20t=80

t=80/20= 4 hours = 4:00 pm when 2nd train catches up to the 1st train