Xanthia can read 100 pages per hour and Molly can read 50 pages per hour. If they each read the same book, and the book has 225 pages, how many more minutes than Xanthia would it take for Molly to finish reading the book?
X takes 225/100 = 2.25 hrs = 2 + 1/4 hrs = 2 hrs 15 min to read the book
M takes 225/50 = 4.5 hrs = 4 hrs 30 mi to read the book
M takes 2hr 15 min more = 2(60) + 15 = 135 min more
We actually may have guessed this....since M reads 1/2 as fast as X, she takes twice as long !!!!