Answer:
velocity in problems per hour = 4 per hour
so correct option is b. 4 per hour
Explanation:
given data
worked on homework time = 1.5 hour
completed = 6 problems
to find out
What is the velocity in problems per hour
solution
we know that Shirley solve complete 6 accounting homework problem in 1.5 hour so her velocity in problems per hour will be as
velocity in problems per hour =
..................1
put here value we will get
velocity in problems per hour = 
velocity in problems per hour = 4 per hour
so correct option is b. 4 per hour