William's typical running speed is 6 mi/h. The difference between his fastest speed and his typical speed is 1.5 min. The equatio
f-1.5 = 6 can be used to represent this problem, where fis William's fastest speed. What is William's fastest speed?

A) 4.5 mi/h
B) 5.5 mi/h
C)6.5mi/h
D) 7.5 mi/h