paper test P P+4 P+11 even or odd?

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paper test P P+4 P+11 even or odd?

by ifthyder » Wed Sep 17, 2008 12:11 am
answer is D. how
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test 31 ds 6.JPG

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by shalen78 » Wed Sep 17, 2008 2:14 am
P, P+4, P+11 = 3 P +15
or
P+5 = Even Number

therefore

P must be odd and the first equation is sufficient

P - 3, P, P +11
3P + 8 = odd

If P is 1...you can have 11, P is 3 you can have 13...1,3 and any odd number satisfies the 2nd condition.

Therefore the 2nd equation is also sufficient.

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by nitin86 » Wed Sep 17, 2008 10:20 am
shalen78 wrote:P, P+4, P+11 = 3 P +15
or
P+5 = Even Number

therefore

P must be odd and the first equation is sufficient

P - 3, P, P +11
3P + 8 = odd

If P is 1...you can have 11, P is 3 you can have 13...1,3 and any odd number satisfies the 2nd condition.

Therefore the 2nd equation is also sufficient.
I think some scenarios are missed in the above reasoning.

Sum of 2 number can be even when
(1) both the numbers are even
(2) both the numbers are odd

Take stmt 1 , one of the reasoning is given by @shalen78.

But for scneairo when 2 of the 3 numbers are odd and one is even, then also the sum of the 3 numbers will be even. for eg

Odd Odd Even
P P+4 P+11

here, ASSUMING that if P is odd, and we analyze, the above scneario, then if P is odd, then P+4 is also odd (even + odd = odd), and P+11 will be even (odd + odd = even).

so P is odd, P+4 is odd, and P+11 is even and sum of these is even

hence from stmt 1 P can be even as well as odd...stmt 1 insufficient.

Same reasoning also goes for stmt 2

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by shalen78 » Wed Sep 17, 2008 3:30 pm
P can not be an even number in Statement 1 (it invalidates the condition).

If P is even, i.e. 4...the sum of P, P+4, P+11 is equal to 4+8+15 = 27. This is not what statement 1 says. Statement 1 says that the sum of P, P+4 and P+11 must equal some even number.

If P is odd, i.e. 5 the sum of P, P+4, P+11 is equal to 5+9+16 = 30. This is exactly what Statement 1 tells you. The sum of the P, P +4 and P + 11 equals some EVEN number.

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by nitin86 » Thu Sep 18, 2008 6:12 am
shalen78 wrote:P can not be an even number in Statement 1 (it invalidates the condition).

If P is even, i.e. 4...the sum of P, P+4, P+11 is equal to 4+8+15 = 27. This is not what statement 1 says. Statement 1 says that the sum of P, P+4 and P+11 must equal some even number.

If P is odd, i.e. 5 the sum of P, P+4, P+11 is equal to 5+9+16 = 30. This is exactly what Statement 1 tells you. The sum of the P, P +4 and P + 11 equals some EVEN number.
yeps...u r right...i read the first scenario as P = even...