Due to a fuel shortage, the speed limit on a major highway was lowered 5 miles per hour. Assume that a certain motorist always drives at the legal speed limit. If he were able to drive 99 miles in 2 1/5 hours at the original speed limit, how long will it take him to drive 100 miles at the new speed limit?
Pls help. Thanks in advance.
NOTE: the correct answer is 2 hours and 30 minutes.