Mr. anderson drove 168 miles in 3 1/2 hours. he then drove the next 2 1/4 hours at a rate of 5 miles an hour faster than the first rate. how many miles did mr. anderson drive during 5 3/4 hours? (middle school)

Remember that distance = rate times time.

First distance = 168 miles; time was 3.5 hours.  Rate was 48 mph.
5 miles per hour faster than that was 53 mph.

Second distance = (2 1/4 hours)*(53 mph) = 119.25 miles

Total distance driven in those 5 3/4 hours:  168 mi + 119.25 mi = 287.25 mi