The distance between port M and port N is 162m. A ship left port M with a speed of 45 mph. In 45 minutes another ship left port N and went towards the first ship with a speed of 36 mph. How long after the departure of the first ship will the two ships meet?

900 min = 15 hours

Step-by-step explanation:

when we convert the velocities of the ships into miles / min we get

45mph = 45m/60min = 0.75m/min

36mph = 36m/60min = 0.6m/min

The equations determining the distances of the ships from the port M (set at x=0) are

D1 = 0.75t (for 45mph ship)

D2 = 162 + 0.6 (t-45) (for 36mph ship)

The solution to these equation lie at t = 900 minutes; therefore the two ships will meet 900 minutes after the departure of the first ship.