Fractions

[Mendoza]

In Guide 2 on page 53 there is reference to rounding which I am confused on.

Approximately what is 10/22 of 5/18 of 2,000. Is the idea here to round one of the fractions up and the other down? Does it matter if I had rounded 10/22 down rather than up? When I did the problem I rounded 10/22 to 1/2 and 5/18 to 1/3 which gave me the wrong answer.

Page 153 #19. I keep getting 10/3 as an answer. Did the book make a mistake in the answer section as the question says 0.2 and the solution has 0.02?

Page 155 #1. For column A I arrived at 3/(x-3)(8) versus column B with 3/8. I remember in one class we were told to deal with the columns as inequalities. Could I eliminate 3/8 from each column? When I did this I was unclear if the "new" Column B became 1 or 0 when I eliminated 3/8. My "new" Column A was 1/ (x-3).

Thanks for the guidance.

[tommywallach]

Hey Mendoza,

In the future, try to put each question in a separate thread. I know it's annoying, but it'll be really hard for anyone else to search this stuff. : )

For your first question, take a look at what comes later on the page. If you round 10/22 to 1/2, you are actually rounding UP, not DOWN. 10/22 is LESS than 1/2 (11/22 = 1/2), so you rounded it up.

When you then rounded 5/18 to 1/3, you rounded up again. This throws the answer way off. The book actually takes on JUST that situation at the bottom of the page. If you ever round twice, try to compensate (round one thing up, and another down).

For your second question, you're totally right. The answer is 10/3. The book has a typo. It will be corrected in the next edition.

For your third question, that's absolutely right. However, remember that you are DIVIDING both columns by 3/8, not SUBTRACTING (because you're MULTIPLYING 3/8 by 1/(x-3) in the first column). So when you divide column B by 3/8, you just get 1. This will always be bigger than Column A, because Column A = 1/(x-3), and we've been told x > 4.

Hope that helps!

-t