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Miles and gallons problem

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Miles and gallons problem

by refreshment » Tue Feb 17, 2009 4:52 am
On a recent trip Cindy drove her car 290 miles, rounded to the nearest 10 miles and used 12 gallons of gasoline rounded to the nearest gallon.
The actual number of miles per gallon that Cindy's car got on this trip must have been between:

A) 290/12.5 and 290/11.4
B) 294/12 and 284/11.4
C) 284/12 and 295/12
D) 284/12.5 and 295/11.4
E) 295/12.5 and 284/11.4
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by DanaJ » Tue Feb 17, 2009 5:06 am
You have a problem of minimum versus maximum here.
The maximum miles per gallon will be (max distance)/(min no. gallons). Since the distance is rounded to the nearest 10 miles, then max distance can only be 294. Since the gallons she used are rounded to the nearest gallon, then min no. gallons will be 11.6
This makes maximum miles per gallon 294/11.6

Now, the minimum miles per gallon will be (min distance)/(max no. gallons). Min distance will be 286, while max no. gallons will be 12.4. This makes minimum miles per gallon 286/12.4

This means that her gas mileage is between 286/12.4 and 294/11.6. I don't see this option in the answers, so I might be wrong.... What is the OA?
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by refreshment » Tue Feb 17, 2009 5:38 am
Have no idea what the OA is, it is a task which i have problems to solve.
But i think the way you do, except that 285-294 will be rounded off to 290, not 286-294....
the same with gallons, 11.5-12.4 is 12 gallons rounded.
But that doesn't change the situation. No matter there is no such answer. :(
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by DanaJ » Tue Feb 17, 2009 6:11 am
Yeah, you are right about 285 and 11.5.
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by anniev2 » Mon Feb 23, 2009 1:42 pm
Yes, the OG is wrong and they issued a correction to this question.
Attachments
Correction to OG11.jpg
correction to the problem in the post
CorrectionsFinal82006.pdf
List of all correction to OG 11 guide
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by anniev2 » Mon Feb 23, 2009 2:08 pm
The above is the correction was issued by OG, however i still think its wrong....?

290 miles rounded to the nearest 10 means the number is between 285 - 294

285 286 287 288 289 290 291 292 293 294

* round up to 290
*round down to 290

12 gallons rounded to the nearest gallon means the number was between 11.5 - 12.4

11.5 11.6 11.7 11.8 11.9 12.012.1 12.2 12.3 12.4

* round up to 12.0
*round down to 12.0

So the number of miles would be between the smallest and the largest numbers.

Smallest is 285/12.4
Largest is 294/11.5

Smallest = Smallest # of Miles Driven
________Largest # of Gallons Used


Largest= Largest # of Miles Driven
______Smallest # of Gallons Used
Attachments
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