Fractions: Sheets of Paper LeftDate: 08/07/97 at 11:57:37 From: Barton, Dana Subject: Word Problem I have a question about a word problem involving fractions. Maybe you can help. An office got a new copier and was given 800 sheets of paper. On the first day they used 1/3 of the paper. On the second day they used 1/5 and on the 3rd they used 1/6 of the paper. How many sheets of paper were left? Dana Barton Date: 08/30/97 at 11:34:42 From: Doctor Sonya Subject: Re: Word Problem Dear Dana, To solve word problems it is necessary to translate mathematical thoughts expressed in words into mathematical symbols that we can manipulate and simplify. For instance, the words "1/3 of the paper" can be written mathematically as 800/3. If we look at what is going on in this office, as paper is used it is being subtracted from the original amount of 800 sheets. We want an expression that models what is going on. If we understand the situation we can arrive at the correct answer. So if on day one, one third of the paper is used, we are left with 800 - 800/3 sheets of paper. On day two we use 1/5 of the paper, which is 800/5. Thus after day two, we will have (800 - 800/3) - 800/5 sheets of paper. If you do the same type of calculation for day three, you can find out how much paper was used that day, and subtract that also to get the final answer. There is another possible interpretation of your word problem, one that makes it a little bit more complicated. We did the problem assuming that "on the second day they used 1/5 of the paper" means that they used 1/5 of the original 800 sheets. It might also mean that they used 1/5 of the number of sheets that were left over after the first day. If you remember, after the first day there were 800 - 800/3 sheets of paper left. If we use up 1/5 of that on the second day, how much would be left? If you have any more questions, please write us back. -Doctors Cheryl and Sonya, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
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