A college professor with several hundred students has office hours between classes to provide extra help when needed. His classes on Monday are from 9:00 AM to 10:45 AM and 2:30 PM to 3:45 PM. It takes him 5 minutes to walk from the classroom to his office, and he takes a lunch break from 12:00 PM to 1:00 PM. On a particular Monday, he plans to grade tests, which have all multiple-choice questions. If each test consists of 50 questions and it takes him 4 seconds to mark each question right or wrong, how many complete tests can he mark during his office hours if no students come for help? Assume that he does not take the time to add up the scores until after his afternoon class.
A. 46
B. 47
C. 54
D. 55
Answer:A
A college professor with several hundred students has office hours between classes to provide extra help when needed. His classes on Monday are from 9:00 AM to 10:45 AM and 2:30 PM to 3:45 PM. It takes him 5 minutes to walk from the classroom to his office, and he takes a lunch break from 12:00 PM to 1:00 PM. On a particular Monday, he plans to grade tests, which have all multiple-choice questions. If each test consists of 50 questions and it takes him 4 seconds to mark each question right or wrong, how many complete tests can he mark during his office hours if no students come for help? Assume that he does not take the time to add up the scores until after his afternoon class.
A. 46 B. 47 C. 54 D. 55
Explanation: A