You should do your own homework! Still, I will give the answer
1-1/3-2/7 = 8/21
2007-01-17 10:51:26
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answer #1
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answered by Anonymous
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If x is his total study time, and he lost 1/3 of it, then he should have x - (1/3)x remaining. ("of" means "multiply".) Additionally, he lost another 2/7 of his total time, so he actually has x - (1/3)x - (2/7)x. Find a common denominator to subtract these fractions. You've got a 3 and a 7 in the denominators, so go with 21.
(21/21)x - (7/21)x - (6/21)x =
(21 - 7 - 6)x/21 =
(8/21)x
So he has 8/21 of his study time left.
Another way to think of this is that the fraction representing his whole study time is 1/1, or just "1" (one whole). So take 1 - 7/21 - 6/21 and you get 8/21.
2007-01-17 10:56:25
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answer #2
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answered by Anonymous
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Well, the remaining study time is given by 1 - (1/3) - (2/7). Any time you subtract a fraction from a whole, you subtract it from one. (Kind of like if I take 1/3 and 2/7 of your 1 pizza.)
So we have 1 - 1/3 - 2/7. The next step is to get common denominators for them since we can't easily subtract them in this form. The most direct way to find a common denominator is to multiply the two denominators together. (The result MUST be divisible by both 3 and 7).
3 * 7 is 21. Now let's convert those fractions into something divided by 21.
1/3 * (7/7) = 7/21. (I can multiply 7/7 to 1/3 and still not change it because 7/7 is 1, and any number multiplied by 1 is itself.)
Likewise with 2/7:
(2/7) * (3/3) = 6/21.
With 1, we multiply (21/21) and get ... 21/21. :-)
So now we have 21/21 - 6/21 - 7/21. Since they have like denominators now, we can subtract and get 8/21.
Hope that helped!!
UMRmathmajor
2007-01-17 10:53:56
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answer #3
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answered by UMRmathmajor 3
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We need to find a common denominator in order to add these fractions. I always multiply the Denominators it's easier for me. 3 * 7 is 21 so I'm going to use 21 as my common denominator.
(1/3) 3 goes into 21, 7 times and 7 times 1 is 7...So 1/3 = 7/21
(2/7) 7 goes into 21, 3 times and 3 times 2 is 6...So 2/7 = 6/21
Now we can add these fractions by adding the numerators across and carrying our denominator over.
7/21 + 6/21 = 13/21
Now that's how much time Jon has used. To find out how much he has left, we'll take 13/21 from 1 or 21/21. (I use 21/21 because we need a common denominator in order to subtract)
21/21 - 13/21 = 8/21. That's how much of his study time Jon has left.
If you can, I know a lot of the kids I teach prefer to use decimals rather than fractions. So if you want go ahead and divide 1 by 3, and 2 by 7 add your answers together and subtract from 1. Just beware, your answers aren't going to be as accurate because 1/3 is 0.3 repeating.
Hope this helped, Good Luck with your Math.
2007-01-17 10:53:09
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answer #4
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answered by Chaney34 5
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1/3+2/7=7/21+ 6/21=13/21 study time used.
7/7-13/21=21/21-13/21= 8/21 study time remaining.
(7/7 is the total study time)
2007-01-17 11:28:20
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answer #5
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answered by Max 6
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First figure your lowest comon denominator--- 3 x 7 = 21
1/3 = 7/21. 2/7 = 6/21
7/21 + 6/21 = 13/21.
1 = 21/21. 21/21 - 13/21 = 8/21 remaining.
2007-01-17 10:54:44
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answer #6
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answered by Erwin B 3
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1/3 +2/7= 13/21
21-13= 8
8/21 remains
2007-01-17 11:18:19
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answer #7
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answered by lionheartlisa91 3
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50% of "stable self sustaining" women human beings have the IQ of a toad... and could in all probability connect with a valuable guy in the different case. Its kinda tricky to have a ninety seven IQ and alter right into a doctor and notwithstanding if by some fluke you probably did... who the hell desires to work out a doctor with a ninety seven IQ??????!!!!?????!!?? and men are purely extremely extra advantageous off. the huge-unfold male IQ is 5-7 factors bigger than women human beings yet that keeps to be approximately 30 factors too low to be waiting to layout a 40 tale development or suspension bridge or something. i'm above huge-unfold in IQ. My dads IQ replace into a hundred and fifty five (accepted of production facility proprietors. they're ALL geniuses) and my mothers is approximately a hundred and one-107 and that i inherited a pass between theirs genetically. If my mom's IQ have been additionally over a hundred and fifty... i might have invented a treatment for aids.
2016-10-07 07:45:29
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answer #8
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answered by ? 4
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8/21 of his time remains.
2007-01-17 10:50:36
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answer #9
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answered by Anonymous
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