Question

Sean read 15 of a book in 112 hours.

Answer 1

Sean read 15 of a book in = 112 hours, 
so, 1 of a book in = 112/15

Now, 12 of a book would be: 112/15 * 12 = 112/5 * 4 = 89.6

89.6 = 89 6/10 = 89 3/5

In short, Your Answer would be 89 3/5 hours

Hope this helps!