What if…
Sam read 1/5 of a book on the 1st day, 20 pages on the 2nd day and 1/6 of the remaining pages on the 3rd day. He read the remaining 1/2 of the book on the 4th day. How many pages were there in the book?
Show how you would find the answer to the problem.
Let P be the number of pages
(1/5)P = 1st day
20 = second day
(1/6)( P - (1/5)P -20) = (1/6) ((4/5)P - 20) = (2/15)P - 10/3 = third day
(1/2)P = fourth day
(1/5)P + 20 + (2/15)P -10/3 = (1/2)P multiply through by 60
12P + 1200 + 8P - 200 = 30P
1200 - 200 = 30P -20P
1000 = 10P
P = 1000 / 10 = 100 pages