Mr. Anderson drove 168 miles in 3 1/2 hours:

d1 = 168 mi

t1 = 3 1/2 hr

t1 = 3.5 hr

v1 = the first rate

v1 = d1/t1

v1 = 168/3.5

v1 = 48 mph

He then drove 2 1/4 hours at a rate of 5 miles an hour faster than the first rate:

t2 = 2 1/4 hr

t2 = 2.25 hr

v2 = v1 + 5

v2 = 48 + 5

v2 = 53 mph

d2 = the distance

d2 = v2*t2

d2 = 53*2.25

d2 = 119.25 mi

during the total time 3 1/2 + 2 1/4 = 5 3/4 hr Mr. Anderson drove:

d1 + d2 = 168 + 119.25 = 287.25 mi.