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June 25th, 2012, 09:28 AM   #1
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Solve. Express in lowest terms.

I just completed 20 questions in preparation for the GED test and out of the 20 questions I failed two. Both of these questions are word problems that need to be solve and then express in lowest terms. Just to give a quick example, say if you withdrew $40 from your savings account. You spent $24 at the food market. What fraction of the withdrawal did you spend at the food market?

I know this is a fairly easy word problem to solve, but I don't understand which number comes first (numerator over denominator or vice versa). For example, I reduce 40/24 and get 5/3. I put 5/3 as my answer. But when I went back and look at the answer sheet the answer was 3/5. Why is the answer 3/5 instead of 5/3? This confused me and throws me off. I know that in the real GED test, they will intentionally have this kind of word problem with both on the answers choices : 5/3, 3/5, etc. and only one of the correct one. So how do I know which one is one out of the two? I notice that in the word problem the last sentence says "What fraction of the withdrawal did you spend at the food market"? This should be a clue as to what the answer is, but I don't quite understand it. Can somebody clarify this a little more better?
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June 25th, 2012, 10:13 AM   #2
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Re: Solve. Express in lowest terms.

What fraction of the whole is the part?
The part is 24 out of the 40 (which makes up the whole).
24 out of 40.
3 out of 5
3/5.

Another way to make fractions is to use the rule
"is"/"of".

What fraction of [the withdrawal amount] is [the amount you spent]?
So the "is" number = 24
And the "of" number = 40.

"is"/"of" = 24/40 = 3/5
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June 25th, 2012, 04:04 PM   #3
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Re: Solve. Express in lowest terms.

Hello, grace25!

You're not alone in your confusion.

Five out of four people have trouble with fractions.

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June 25th, 2012, 04:33 PM   #4
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Re: Solve. Express in lowest terms.

A common line in advertising is "... for a FRACTION of the cost!"

The only things I hate more is when people say, "XXX has happened A NUMBER OF TIMES"

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June 25th, 2012, 06:56 PM   #5
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Re: Solve. Express in lowest terms.

Whenever someone tells me they are going to give x % effort, where 100 < x, I feign disappointment, and ask why they can't give (x + 1)%. :P

It makes me very popular, especially with the ladies.
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June 25th, 2012, 08:15 PM   #6
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Re: Solve. Express in lowest terms.

Quote:
Originally Posted by grace25
.... say if you withdrew $40 from your savings account. You spent $24 at the food market. What fraction of the withdrawal did you spend at the food market?
REASON it out...
You know if you spent the full $40, then you spent 100% ; right?
Then if you spent $20, you spent 50% ; OK?
Soooooo if you spent $24, then that's a bit over 50%.....get my drift?
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June 26th, 2012, 05:21 AM   #7
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Re: Solve. Express in lowest terms.

Quote:
Originally Posted by The Chaz
What fraction of the whole is the part?
The part is 24 out of the 40 (which makes up the whole).
24 out of 40.
3 out of 5
3/5.

Another way to make fractions is to use the rule
"is"/"of".

What fraction of [the withdrawal amount] is [the amount you spent]?
So the "is" number = 24
And the "of" number = 40.

"is"/"of" = 24/40 = 3/5
Right, I see now. I misunderstood the word problem. It ask for what fraction of the withdrawal did you spend. So I know part of the whole ($40) is $24. If I reduce both these numbers it would be 5/3. But, the 3 is part of the whole because it belongs to the $24. The 5 belongs to the $40. So the answer is 3/5 instead.
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June 26th, 2012, 05:59 AM   #8
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Re: Solve. Express in lowest terms.

Quote:
Originally Posted by soroban
Hello, grace25!

You're not alone in your confusion.

Five out of four people have trouble with fractions.

I'm doing good with fractions. The problem for me is lack of reading comprehension. We can say the same is also true for word problems that deal with ratio. I learn that I have to write the terms of ratio exactly in the same order as the word problem. If the question ask to solve for X (how much, how many), writing the proportion in the exact order and place the X in the same order as the original question is asking.

For example, if you use 315 calories to jog in 3 miles. How many calories will be used if you jog 10 miles?

1. Write the ratio in the exact order as in the word problem.

315 X
3 = 10

2. Solve by cross multiplying then divided by 3.

3. The "X" is always in the same order as the original question is asking. In this problem, the "X" is on top because the question is asking for how many calories. So I place the "X" to match the first fraction to match calories. So it depends on what the question is asking will determine where the "X" will be place. Not all word problems is the same. This can be said with word problems that deal with fractions too. I think I'm starting to understand now.
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June 26th, 2012, 06:04 AM   #9
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Re: Solve. Express in lowest terms.

Some problems the "X" is place at the bottom. So it depend what the question is asking.
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