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May 11th, 2012, 04:29 AM   #1
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Percentages problem need help adding percentages please

I need 40% overall to pass my exam. So far I have got:

55% of an exam worth 45% of overall grade, and
75% of an essay worth 10% of overall grade

I have one more exam, worth 45% of the overall grade. What is the minimum percentage score I need to achieve to get an overall grade of 40%?

I have no idea how to do the math, so any help is great.

Thanks
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May 11th, 2012, 09:30 AM   #2
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Re: Percentages problem need help adding percentages pleas

Let x represent the minimal score you need. So we have:

0.450.55 + 0.100.75 + 0.45x = 0.40

0.2475 + 0.075 + 0.45x = 0.40

0.3225 + 0.45x = 0.40

0.45x = 0.0775

x = 0.17222...

Hence, the minimal score is 17 2/9%
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May 11th, 2012, 09:33 AM   #3
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Re: Percentages problem need help adding percentages pleas

Ah, you're great. Thanks a lot.

I've always wondered how to do this.
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May 11th, 2012, 06:56 PM   #4
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Re: Percentages problem need help adding percentages pleas

Quote:
Originally Posted by BellEnd
I've always wondered how to do this.
always ?
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May 25th, 2012, 02:56 PM   #5
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Re: Percentages problem need help adding percentages pleas

You can just imagine a month old baby, lying in his crib, wondering how to do problems like this!
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