Question

Sheila leaves on a long trip driving at a steady rate of 30 miles per hour. Her sister Allison leaves from the same location traveling to the same destination 2 hours later. She drives at a steady rate of 60 miles per hour. How long after Sheila leaves home will Allison catch up?
a.
4 hours
b.
5 hours
c.
3 hours
d.
2 hours