Answer:
150 km
Explanation:
You want to know the number of kilometers each train has traveled when they meet. The first goes 60 km/h and has a half-hour head start. The second goes 75 km/h.
Setup
At t hours after 10 am, the distance of the first train from Kanpur will be ...
distance = speed × time
distance = 60t
At t hours after 10 am, the distance of the second train from Kanpur will be ...
distance = 75(t -1/2) . . . . . . the distance is 0 at 10:30 am, 1/2 after 10 am
These distances will be equal when ...
60t = 75(t -1/2)
Solution
The time at which the trains meet will be the solution to the above equation.
60t = 75t -37.5 . . . . eliminate parentheses
0 = 15t -37.5 . . . . . . subtract 60t
0 = t -2.5 . . . . . . . . . divide by 15
2.5 = t . . . . . . . . . the trains meet 2.5 hours after the first one leaves
The distance traveled by each of the trains is the same at that time. It will be the distance traveled by the first train:
60t = 60(2.5) = 150 . . . . km
The two trains will be together 150 km from Kanpur.