Question 1196948
<br>
The distance the second ship needs to make up is 10 miles; the rate of catching up is the difference between the two speeds, which is 40-30 = 10mph.<br>
I assume you are familiar with the basic formula<br>
time = distance / rate<br>
It is similarly true that<br>
time = (difference in distances) / (difference in rates)<br>
So the number of hours required for the second ship to catch up to the first is 10/10 = 1.<br>
ANSWER: 1 hour<br>