Question

A ship sails at 15 miles per hour, while it can motor at 5 miles per hour. It sails for 6 hours to its destination but has to motor on the return trip home. How long does it take for the return trip?

Answer 1

Hello!

The answer is:

It will take 18 hours for the return trip.

Why?

To calculate how long does it take for the return trip, we need to calculate the distance between it destination and the starting point.

We know that the ship sails at 15 miles per hour (mph) for 6 hours, so, calculating the distance we have:

$x=x_o+v*t\\\\x=0+15mph*6hours=90miles$

We know that the distance between the destination and the starting point is 90 miles, now, to calculate how long does it take the return trip, we need to use the motor speed rate which is equal to 5 miles per hour (mph), so, calculating we have:

$Distance=v*t\\\\t=\frac{Distance}{v}=\frac{90miles}{5mph}=18hours$

Therefore, we have that it will take 18 hours for the return trip.

Have a nice day!