Question

Professor Lam is grading papers in the teachers' lounge. He has already finished grading 6 assignments, and is grading 4 more assignments per hour. His teaching assistant just came in to help him. He can grade at a rate of 5 assignments every hour. At some point, they will be finished and will have graded the same number of papers. How long will that take? How many assignments will they each have graded?

Answer 1

Answer:

Step-by-step explanation: If Professor Lam grades 4 papers per hour, in 11 hours he will graded 44 papers. (11 x 4= 44). He had previously graded 6 papers giving him a total of 50 papers graded. His assistant can grade 5 papers per hour, thus it would take him 10 hours to grade the same amount of papers as Professor Lam. (10 x 5= 50) Thus: 11 hours Professor Lam 50 papers graded; 10 hours his assistant 50 papers graded.