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Q142 Quant Problem Solving OG 13th Edition

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Q142 Quant Problem Solving OG 13th Edition

by Orla M » Fri Jan 04, 2013 12:32 am
Hi, I understand how to go about this problem but one thing still boggles me. I'm trying to figure out why 295 would be possible to round up to 290 to the nearest 10th as I would assume 295 falls closer to 300, or does that not qualify as nearest 10th? Same thing for the gallons story, where 12.5 would be considered 12 to the nearest gallon as I would, again, have assumed it being closer to 13.

Can someone please help to explain why this is the case in this question despite the rules of any number such as 15 rounded up to the nearest 10th would ordinarily be 20 - or am I missing something here?

Thanks. :D
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by Sam_hellboy » Fri Jan 04, 2013 1:11 am
while rounding up.is the number is between 0.1 to 0.5 you can stick to the original number
i.e 12.5 = 12. When the decimal is between .6 to .9 you can round it up to the next number i.e. 13.
Everyone follows this approach.There is no specific theorem or rule for this.Hope this helps..
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by The Iceman » Fri Jan 04, 2013 2:10 am
Sam_hellboy wrote:while rounding up.is the number is between 0.1 to 0.5 you can stick to the original number
i.e 12.5 = 12. When the decimal is between .6 to .9 you can round it up to the next number i.e. 13.
Everyone follows this approach.There is no specific theorem or rule for this.Hope this helps..
This is incorrect!

Basically, if you have a number 12.x, then for a number to be estimated to 13, "x" must be greater than or equal to 5 and not just greater than 5. Other wise the number can be estimated back to 12.


12.5 approximates to 13 and not 12.

For a decimal number D to approximate to 12, it must be in the range 11.5 <= D < 12.5

For a number A to approximate to 290 to the nearest 10 places, 285 <= A < 295

So, the two extremities for the question at hand are 285/12.5 and 295/11.5 (both excluded)

Hence the right range must be between 285/12.5 and 295/11.5 (eclusive of the boundary values)
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by gander123 » Fri Jan 04, 2013 4:12 am
Fully agree with Iceman.

I can only tell you from Germany, what is commonly accepted is to round oup from 5 including 5 and only round down from 1 up to and including 4. I assume its like that at least all over Europe.

Cheers,

Tobi
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by Orla M » Fri Jan 04, 2013 11:28 am
Thanks for the quick reactions. Iceman, Gander, thanks for the confirmation of the rule. Exactly my understanding but was thrown off that the OG explanation included the 12.5 and 295 which made me doubt the rounding rule. Your responses help clarify the inclusion of boundaries.
Last edited by Orla M on Fri Jan 04, 2013 1:00 pm, edited 1 time in total.
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by Sam_hellboy » Fri Jan 04, 2013 12:12 pm
The Iceman wrote:
Sam_hellboy wrote:while rounding up.is the number is between 0.1 to 0.5 you can stick to the original number
i.e 12.5 = 12. When the decimal is between .6 to .9 you can round it up to the next number i.e. 13.
Everyone follows this approach.There is no specific theorem or rule for this.Hope this helps..
This is incorrect!

Basically, if you have a number 12.x, then for a number to be estimated to 13, "x" must be greater than or equal to 5 and not just greater than 5. Other wise the number can be estimated back to 12.


12.5 approximates to 13 and not 12.

For a decimal number D to approximate to 12, it must be in the range 11.5 <= D < 12.5

For a number A to approximate to 290 to the nearest 10 places, 285 <= A < 295

So, the two extremities for the question at hand are 285/12.5 and 295/11.5 (both excluded)
Hence the right range must be between 285/12.5 and 295/11.5 (eclusive of the boundary values)
Thanks for correcting me..
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