What is the hundredth digit of the decimal Z?
1. The tenth digit of 100Z is 2
2. The unit digit of 1000Z is 2
GMAT prep decimal
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I think the answer is D.
Here's how..
1. The tenth digit of 100Z is 2.
Therefore:
100Z = .2XXXXXX (the X's dont matter)
Hence,
Z = .2XXXX / 100
Or
Z = .002XXXXX
So the hundredth digit of Z is 0. Sufficient.
2. The unit digit of 1000Z is 2. This is basically saying the same thing as statement 1. However, just taking this alone:
1000Z = 2.XXXXX (again the X's dont matter)
Hence,
Z = 2.XXXXX / 1000
Or
Z = .002XXXX
So the hundredth digit of Z is 0. Sufficient Again.
Therefore the answer is D.
Here's how..
1. The tenth digit of 100Z is 2.
Therefore:
100Z = .2XXXXXX (the X's dont matter)
Hence,
Z = .2XXXX / 100
Or
Z = .002XXXXX
So the hundredth digit of Z is 0. Sufficient.
2. The unit digit of 1000Z is 2. This is basically saying the same thing as statement 1. However, just taking this alone:
1000Z = 2.XXXXX (again the X's dont matter)
Hence,
Z = 2.XXXXX / 1000
Or
Z = .002XXXX
So the hundredth digit of Z is 0. Sufficient Again.
Therefore the answer is D.
- simplyjat
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You are wrong in assumingjain0069 wrote:I think the answer is D.
Here's how..
1. The tenth digit of 100Z is 2.
Therefore:
100Z = .2XXXXXX (the X's dont matter)
Hence,
Z = .2XXXX / 100
Or
Z = .002XXXXX
So the hundredth digit of Z is 0. Sufficient.
2. The unit digit of 1000Z is 2. This is basically saying the same thing as statement 1. However, just taking this alone:
1000Z = 2.XXXXX (again the X's dont matter)
Hence,
Z = 2.XXXXX / 1000
Or
Z = .002XXXX
So the hundredth digit of Z is 0. Sufficient Again.
Therefore the answer is D.
100Z = .2XXXXXX
actually it should be
100Z = XXXX.2XXXXXX
simplyjat
Jeez... *** Slap across the face ***... Thanks dude... Just tells me why I am so bad at DS eh ...
Note to self: Will always triple and quadruple check my answers before posting again...
Thanks for pointing out the mistake in my reasoning though...
Note to self: Will always triple and quadruple check my answers before posting again...
Thanks for pointing out the mistake in my reasoning though...
- simplyjat
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Don't be harsh on yourself, DS just requires some practice and patience.jain0069 wrote:Jeez... *** Slap across the face ***... Thanks dude... Just tells me why I am so bad at DS eh ...
Note to self: Will always triple and quadruple check my answers before posting again...
Thanks for pointing out the mistake in my reasoning though...
simplyjat
-
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E for surearorag wrote:What is the hundredth digit of the decimal Z?
1. The tenth digit of 100Z is 2
2. The unit digit of 1000Z is 2
1. Doesn't tell you hundreths
2. Doesn't tell you hundreths
What else is there to consider?
- karthikpandian19
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OA is E,
Can any GMAT EXPERT provide detailed explanation for this as my answer is tending towards A
Please clarify
Can any GMAT EXPERT provide detailed explanation for this as my answer is tending towards A
Please clarify
- eagleeye
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All right, I am going to settle this debate. btw, the correct answer is E. Here's how.
"What is the hundredth digit of the decimal Z?
1. The tenth digit of 100Z is 2
2. The unit digit of 1000Z is 2"
Let Z =abcd.efgh (where a,b,c,d,e,f,g,h are all integers) (we can go farther on each side, lets just assume this without loss of much generality). The hundredth digit here is f; if we can determine d either from 1 or 2 or both, the answer won't be E.
Now:
1. 100Z = abcdef.gh; The tenth digit is 2. So, g = 2.
therefore, 100Z=abcdef.2h
No, information about f, INSUFFICIENT.
2. 1000Z = abcdefg.h ; The unit digit is g again, so g = 2.
therefore, 1000Z = abcdef2.h
Again, we don't know what f is, INSUFFICIENT.
Now let's consider them together. Both equations give the same information, i.e. g = 2. Hence C is not a possibility as well. Therefore the correct answer is E.
Point to note: if we were not given the same information (g = 2) in the two equations, we might have been able to find f by subtracting the two equations, or substituting.
Let me know if this helps
"What is the hundredth digit of the decimal Z?
1. The tenth digit of 100Z is 2
2. The unit digit of 1000Z is 2"
Let Z =abcd.efgh (where a,b,c,d,e,f,g,h are all integers) (we can go farther on each side, lets just assume this without loss of much generality). The hundredth digit here is f; if we can determine d either from 1 or 2 or both, the answer won't be E.
Now:
1. 100Z = abcdef.gh; The tenth digit is 2. So, g = 2.
therefore, 100Z=abcdef.2h
No, information about f, INSUFFICIENT.
2. 1000Z = abcdefg.h ; The unit digit is g again, so g = 2.
therefore, 1000Z = abcdef2.h
Again, we don't know what f is, INSUFFICIENT.
Now let's consider them together. Both equations give the same information, i.e. g = 2. Hence C is not a possibility as well. Therefore the correct answer is E.
Point to note: if we were not given the same information (g = 2) in the two equations, we might have been able to find f by subtracting the two equations, or substituting.
Let me know if this helps
If it is asking for what is the hundredths digit of decimal z, isn't z just a digit between 0-9? In that case, isn't isn't any other digit besides the units digit of z=0? e.g. z= 09.00?
Let's assume z=9
1) 100z = 900.00; tenths digit = 0
2) 1000z = 9000.00; units digit = 0
D both alone are sufficient.
Let's assume z=9
1) 100z = 900.00; tenths digit = 0
2) 1000z = 9000.00; units digit = 0
D both alone are sufficient.