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Non zero digits

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Non zero digits

by manik11 » Thu Feb 18, 2016 5:41 am
Does the decimal expression of the fraction X/8 have more than 4 non-zero digits?

1. X is a digit
2. X<10

OA :A

I figured 1/8 is 0.125 and rephrased the question to "0.125X more than 4 non-zero digits?"
Multiplied couple of numbers to 0.125 but didn't got more than 3 non zero digits. Chose D.
Experts...Could you please tell me whether my approach was correct? And more importantly where did I go wrong?
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by DavidG@VeritasPrep » Thu Feb 18, 2016 5:50 am
manik11 wrote:Does the decimal expression of the fraction X/8 have more than 4 non-zero digits?

1. X is a digit
2. X<10

OA :A

I figured 1/8 is 0.125 and rephrased the question to "0.125X more than 4 non-zero digits?"
Multiplied couple of numbers to 0.125 but didn't got more than 3 non zero digits. Chose D.
Experts...Could you please tell me whether my approach was correct? And more importantly where did I go wrong?
The rephrase is certainly valid. 1/8 = .125, so clearly x/8 = x*(.125)
Your problem was assuming that x was an integer. Statement 2 only tells us that x is less than 10, so x could be some horrible decimal that would give us more than 4 non-zero digits in x/8.
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by Matt@VeritasPrep » Fri Feb 19, 2016 2:04 pm
Assuming that x is positive, an integer, rational, etc. is one of the testwriters' favorite tricks, so don't sweat it: if you miss this a few times in practice, it makes you that much more annoyed by it and thus more likely to remember it on test day! :)
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