Question

A train leaves Boston at 4:00p.m. A second train leaves the same city in the same direction at 6:00p.m. The second train travels 42 mph faster than the first one. IF the second train overtakes the first at 8:00p.m., what is the speed of each of the two trains?

Answer 1

v1 and v2 be the speeds
v2=v1+42 mph
Since, they cover same distances in 4 hr and 2 hr respectively
t1 * v1 = t2 *v2
4* v1 = 2 * v2
4v1 = 2(v1+42)
2v1= 84

v1 = 42 mph
and v2= 84 mph