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three digit prime number XYZ

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three digit prime number XYZ

by arora007 » Wed Jun 23, 2010 11:44 am
Code letters X, Y, and Z each represent one digit in the three digit prime number XYZ.
IF neither X nor Y is an odd integer, what is the number represented by XYZ?

1) The sum of the three digits is 7.
2) X - Y > 2

[spoiler]OA is E,
I worked my way upto getting 601 and 403 as the two alternatives and then chose C,
because i was not sure if both of them were prime numbers and time was running out.[/spoiler]

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by hemanthquartz1 » Wed Jun 23, 2010 12:58 pm
403 is not prime. 13 is a factor.
I too feel that C is the answer, as I cannot come up with any other number than 601 which is a prime.
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by jonathan123456 » Wed Jun 23, 2010 1:10 pm
Yeah, C looks like the answer.
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by sumanr84 » Fri Jun 25, 2010 8:10 pm
This question is such a time killer..Phewww !!

Has anyone figured out a quick method to crack it..?
I am on a break !!
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by selango » Fri Jun 25, 2010 9:42 pm
X and Y are even integers.

Z can be any digit from 0 to 9

From stmt1,

x+y+z=7

Since X+Y is an even integer,Z will be an odd integer like 1,3,5,7,9 .

Note that to get 7 X+Y should be even and Z is odd.So

6+1
4+3
are the only ways possible.

The possible scenarios are,

241
421
601
223
403--Not prime

From stmt 2,X-Y>2,Insufficient as many combinations are possible

Combining,

we get 421,601

Hence Insufficient.

SO E
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by Haaress » Sat Jun 26, 2010 2:43 pm
I guess you've forgetten that stmt 2 ,X - Y > 2, disqualifies choice 421 as 4-2 is not greater than 2. So using both statements will result to 601. Thus C.
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by selango » Sat Jun 26, 2010 8:16 pm
Thanks for pointing out.

Then 601 is the only number satisfying both statments.

Hence C
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