Problema Solution

A ship left port A with a speed of 40 mph. In 1 1/4 of an hour, a second ship left the port with a speed of 60 mph. In how many hours and at what distance from port A will the second ship catch up with the first one?

Answer provided by our tutors

Let

v1 = 40 mph

v2 = 60 mph

t = the time of the first ship

t - 1 1/4 = t - 5/4 the time of the second ship

Since distance = speed*time and both ships passed the same distance we have:

v1*t = v2*(t - 5/4)

40t = 60(t - 5/4)

........

click here to see the equation solved for t

........

t = 3.75 hr

t = 3 hr 0.75*60 min

t = 3 hr 45 min is the time of the first shit

3.75 - 5/4 = 3.75 - 1.25 = 2.50 hr = 2 hr 0.50*60 min = 2 hr 30 min

2.50*v2 = 2.50*60 = 150 mi

The second ship will catch up with the first one after 2 hr 30 min and 150 miles from port A.