non-terminating decimal.

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non-terminating decimal.

by uptowngirl92 » Fri Jul 17, 2009 10:21 pm
8103/x is a non-terminating decimal.Which of the following could be a value of x?
a. 2
b. 5
c. 9
d. 12
e. 15

[spoiler]Ans:E[/spoiler]

Elimainated A and B straightaway because we know that 2 or 5 gives us a teminating decimal.Then what??
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by aim-wsc » Fri Jul 17, 2009 10:36 pm
After eliminating A & B you would notice that 8103 is divisible by 3.
Eventually rest of these three options too are divisible by 3. So we reduce C D & E to 3, 4, 5.

now we know 4 & 5 gives us terminating decimals.

Answer is C '9' :)

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Re: non-terminating decimal.

by tohellandback » Fri Jul 17, 2009 10:46 pm
uptowngirl92 wrote:8103/x is a non-terminating decimal.Which of the following could be a value of x?
a. 2
b. 5
c. 9
d. 12
e. 15

[spoiler]Ans:E[/spoiler]

Elimainated A and B straightaway because we know that 2 or 5 gives us a teminating decimal.Then what??
A, B must give terminating decimals
D-since 8103 is divisible by 3. so when divided by 4 it has to be terminating
E- same as above
C- Answer
The powers of two are bloody impolite!!

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Re: non-terminating decimal.

by gmat740 » Sat Jul 18, 2009 6:52 am
uptowngirl92 wrote:8103/x is a non-terminating decimal.Which of the following could be a value of x?
a. 2
b. 5
c. 9
d. 12
e. 15

[spoiler]Ans:E[/spoiler]

Elimainated A and B straightaway because we know that 2 or 5 gives us a teminating decimal.Then what??
Answer has to be C and not E

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by PussInBoots » Sun Jul 19, 2009 3:05 pm
(C), not (E)

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by mehravikas » Sun Jul 19, 2009 11:55 pm
answer has to be C

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by axat » Mon Jul 20, 2009 5:17 am
aim-wsc, I do not understand your approach to the question.

How do you justify reducing C, D and E to 3,4 and 5? What is the principal involved in these questions? I would appreciate it if you could elaborate on these 2 points please.


aim-wsc wrote:After eliminating A & B you would notice that 8103 is divisible by 3.
Eventually rest of these three options too are divisible by 3. So we reduce C D & E to 3, 4, 5.

now we know 4 & 5 gives us terminating decimals.

Answer is C '9' :)

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by sreak1089 » Mon Jul 20, 2009 6:13 am
Looking at 2 and 5, I rule them out as possible answers just as you do. Next, I see that 9/8100 leaves 3 as reminder, which becomes 1/3 which is recurring or non-terminating, i don't even evaluate other options.