A train leaves Boston and travels towards its destination at a speed of 60mph. One hour later, an express train leaves Boston and travels towards the same destination at a speed of 80mph. How far away from Boston is their destination if they arrive at the same time.
Let d be the distance to the destination.
Since the first train traveled for one hour longer than the second train, we can express the time taken by the first train as (d/60) + 1 and by the second train as d/80.
Given that they arrive at the same time, we have the following equation:
(d/60) + 1 = d/80
Multiplying through by 240 (the least common multiple of 60 and 80), we get:
4d + 240 = 3d
Solving for d, we get:
d = 240
Thus, the destination is 240 miles away from Boston.