Problema Solution
At 7 a.m. a train left the station heading directly north at 50 miles per hour. At 9:00 a.m. a bus left the same station heading south at 60 miles per hour. At what time will the train and bus be 650 miles apart?
Answer provided by our tutors
at 7:00 the train left with speed 50 miles per hour towards north.
at 9:00 another train left with speed 60 miles per hour towards south.
at 9:00 am the first train travelled = 50*2 miles = 100 miles, so while starting the second train both were apart 100 miles.
Both were travelling in a different direction and to calculate the distance apart, the speed need to be added for considering effective speed of both the trains.
so the remaing 550 miles and with 50+60 miles/hour it requires = 550/110 hours = 5 hours from 9.00 am...
So at 9+5 (base 12) = 2:00 PM both will be apart=650 miles.