Bill is reading a 216- page book. He needs to read twice as many pages as he has allready read. Using the guess-and-check stratagy to determine how many pages he has read
2006-10-10 10:14:29 · 12 answers · asked by kacak15348 1 in Science & Mathematics ➔ Mathematics
As other people have pointed out, this is an easy problem to solve with a little basic algebra, but you were specifically instructed to use a "guess-and-check" strategy, so:
Start with 50. If he had to read twice as many, that'd be 100. 50 + 100 = 150, which is too low.
Try 75. 75 * 2 = 150, and 75 + 150 = 225. Just a little too high.
Try 70. 70 * 2 = 140, and 70 + 140 = 210.
Try 72. 72 * 2 = 144, and 72 + 144 = 216. Bingo.
He's read 72 pages.
Is that what you meant by "guess and check?"
2006-10-10 10:23:15 · answer #1 · answered by Jay H 5 · 1⤊ 0⤋
He's read a third of the book so far - 72 pages.
Don't need to use the guess-and-check strategy, just need to understand maths!
Let's call the number of pages he's read "Y"
Twice as many pages as Y would be 2 x Y ie 2Y
So to complete the book Bill needs to read: Y + 2Y
Y + 2Y = 3Y
So, 3Y = 216pages
Simple algebra, if 3Y = 216, then Y = 216 divided by 3
Answer Y=72. So, as said at the top, Bill has read 72 pages.
Easy when you know how!!
2006-10-10 17:27:52 · answer #2 · answered by SL 3 · 0⤊ 0⤋
The book has 216 pages?
And he needs to read 2/3 of it?
(2*216)/3 = 72 pages read, 144 pages left
2006-10-10 17:17:10 · answer #3 · answered by Dr. J 2 · 1⤊ 0⤋
Don't need to guess. He has read one third of the book. 216/3 = 72 pages.
2006-10-10 17:28:06 · answer #4 · answered by quatt47 7 · 0⤊ 0⤋
72 read..144 to go. first, form an equation....x+2x=216.
x is the number of pages already read and the 2x symbolizes tha the needs to read twice of what he already read.
if you just solve the equation for x, it is faster..but if you need to specifically use guess and check, then pick a value for x, and keep picking one until the equality works.
2006-10-10 17:28:18 · answer #5 · answered by Anonymous · 0⤊ 0⤋
2x represents the many page he is going to read.
1x means how many pages he already read.
3x is the total of how many page he has read and is going to read. 216/3 = 72=x
so he is going to read 144 pages, and he has read 72 pages.
2006-10-10 18:43:46 · answer #6 · answered by neopetsrockstar10 2 · 0⤊ 0⤋
72 pages
2006-10-10 17:17:47 · answer #7 · answered by h2oracer 1 · 1⤊ 0⤋
bill has read 72 pages or one third of the book
2006-10-10 17:18:07 · answer #8 · answered by wohoofiona 3 · 1⤊ 0⤋
72 pages are read.
144 are to be read yet.
2006-10-10 17:19:16 · answer #9 · answered by syam p 2 · 0⤊ 0⤋
WELL, YOU GOT TO EITHER DIVIDE THE 216 BY 2 AND COME WITH 108 OR EITHER ADD 216 TWICE AND IT'S 426 SO IF HE HAS TO READ TWICE AS MANY AS HE HAS ALREADY READ AND HE HAS ALREAD READ 216 THEN THAT I WOULD THINK THAT YOU WOULD HAVE TO ADD TO GET THE RIGHT ANSWER.
2006-10-10 17:18:28 · answer #10 · answered by dixieprayerlady 3 · 0⤊ 2⤋