Sheila leaves on a trip driving at 30 miles per hour. Two hours later, her sister Allison starts from the same location driving at 60 miles per hour. How long after Allison leaves home will she catch up to Sheila?
4 hours
3 hours
5 hours
2 hours
Let the time Allison takes to catch up to Sheila be x hours.
Since Sheila had a 2-hour head start, her total time would be x + 2.
The distance traveled by both Sheila and Allison when they meet is the same. Therefore, we can set up an equation:
30(x + 2) = 60x
30x + 60 = 60x
60 = 30x
x = 2
Allison will catch up to Sheila 2 hours after she leaves home.
Therefore, the answer is 2 hours.