Question 167421

Distance(d) equals Rate(r) times Time(t) or d=rt;  r=d/t and t=d/r
We are basically told that Train B is 12 min behind Train A.

Let t=amount of time needed for Train B to catch up with Train A after Train B passes the station

Distance train A has travelled from the station when Train B catches up=60*(12/60)+60t
Distance train B has travelled from the station when it catches Train A=80t

When the above two distances are equal, train B will have caught Train A, so:
60*(12/60)+60t=80t
12+60t=80t subtract 60 t from each side
12=80t-60t
20t=12  divide each side by 20
t=12/20=6/10=3/5 hr=36 min----time needed for Train B to catch Train A
Therefore, Train B catches Train A at 12:32 + 36 min=1:08 PM

CK
12+60(3/5)=80(3/5)
12+36=3*16
48=48



Hope this helps---ptaylor