mr. Rodriguez, a college instructor, can grade his class papers in 3 hours while it takes his assistant 4 1/2 hours. If Mr. Rodriguez graded the papers for 1 hour and then left the job for his assistant to complete, how long will it take his assistant to finish grading papers?
R did 1/3 of the job
So A has to do 2/3 of the job
(2/3) (4 1/2) = (2/3)(9/2) = 3 hours
1/3+2/9x=1
2/9x=2/3
x=3 hours
What Damon said
R did 1/3 of the job
So A has to do 2/3 of the job
(2/3) (4 1/2) = (2/3)(9/2) = 3 hours