Question

A ship left a port and sailed east at the rate of 30 miles per hour. One hour later, a second ship left the same port at the rate of 40 miles per hour, also traveling east. In how many hours did the second ship overtake the first ship?​

Answer 1

3 hours

Explanation:

When the ships meet each other, that means the the distance travelled for both ships are the same, that is where the 2nd ship will overtake the ship.

Distance = Speed * Time

So, given information from the question, and letting x be the time in hours (from when the 1st ship departs), we can deduce:

Distance travelled of 1st ship = Distance travelled of 2nd ship

30x = 40(x-1)

30x = 40x - 40

-10x = - 40

x =
`(-40)/(-10)`

= 4

Since we are calculating based on the 2nd ship,

Time taken for 2nd ship to overtake first ship = x - 1 = 4 - 1 = 3 hours.