Explain simply why (C) is the correct answer to: Ronald and Elan are working on an assignment. Ronald takes 6 hrs to type 32 pages on a computer, while Elan takes 5 hrs to type 40 pages. How much time will they take, working together on two different computers to type an assignment of 110 pages?
Options:
(A) 8 hrs 85 min
(B) 8 hrs 18 min
(C) 8 hrs 15 min
(D) 6 hrs 15 min
(E) 3 hrs 15 min. Explanation:
Number of pages typed by Ronald in 1 hour = 32/6 = 16/3
Number of pages typed by Elan in 1 hour = 40/5 = 8
Number of pages typed by both in 1 hour = (16/3 + 8) = 40/3
Time taken by both to type 110 pages = (110 * 3/40) = 8 1/4 = 8 hrs 15 min