A and B start moving in opposite direction . A starts a 9 pm and B starts at 6 pm . A's speed is 40 m/hr and B's speed is 20m/hr . What is the time when they are 240 miles apart .
Question does not mention one important point,weather A and B started from same point and moved towards each other or away from each other.
If I assume A and B started from same point and moved away from each other,
At 9pm distance between them 3*20=60 miles
from 9pm relative speed is 40+20=60,iles per hour
so they will be 240miles apart in another (240-60)/60=3hr or at 12am
