For the first answer, We have to make a rate.
For Mike, one floor can finish in ten hours. (r=1/10), 1 represents floors, and 10 represents hours.
For Patty, one floor can finish in eight ours. (r=1/8)
Add both up. 1/10 + 1/8 = 9/40 of the floor per hour.
1 hour/(9/40 floor) = 40/9 hours which, gets rounded, is 4.44. The answer is C.
For the second answer, the answer is D because if you divide 4/40 (hours/mph), you get 10. So we can divide 10 (1hour/10mph) by 55 and get 5.5.
