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If x, y and z are consecutive integers, and x < y < z, which of the [#permalink]
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Updated on: 07 Oct 2017, 00:59
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If x, y and z are consecutive integers, and x < y < z, which of the following is NOT always true? A. yz is even. B. The average (arithmetic mean) of x, y and z is y. C. y^2 − xz is odd. D. xy < yz E. xyz is even OE D: If x = 2, y = 1 & z = 0 → xy = 2 & yz = 0
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Originally posted by goodyear2013 on 20 Jul 2014, 04:55.
Last edited by Bunuel on 07 Oct 2017, 00:59, edited 1 time in total.
Edited the question.



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Re: If x, y and z are consecutive integers, and x < y < z, which of the [#permalink]
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20 Jul 2014, 05:26
goodyear2013 wrote: If x, y and z are consecutive integers, and x<y<z, which of the following is NOT always true? A. y·z is even. B. The average (arithmetic mean) of x, y and z is y. C. y^2−x·z is odd. D. x·y<y·z E. x·y·z is even OE D: If x = 2, y = 1 & z = 0 → xy = 2 & yz = 0 A. y·z is even. The product of two consecutive integers is always even. Discard. B. The average (arithmetic mean) of x, y and z is y. The average of three consecutive integers is the middle term (y). Discard. C. y^2−x·z is odd. y^2  xz is either odd^2  even*even = odd or even^2  odd*odd = odd. Discard. D. x·y<y·z > if y is negative, then by reducing by it we'd get x > z, which contradicts the stem. E. x·y·z is even. The product of three consecutive integers is always even. Discard. Answer: D.
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Re: If x, y and z are consecutive integers, and x < y < z, which of the [#permalink]
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06 Oct 2017, 23:11
goodyear2013 wrote: If x, y and z are consecutive integers, and x<y<z, which of the following is NOT always true? A. y·z is even. B. The average (arithmetic mean) of x, y and z is y. C. y^2−x·z is odd. D. x·y<y·z E. x·y·z is even OE D: If x = 2, y = 1 & z = 0 → xy = 2 & yz = 0 Hi! Thanks for your post. Could you please rewrite 'yz' instead of 'y.z' in the option A. It seemed 'YZ" to me and as a result I ended up choosing option A as the correct answer. Cheers



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Re: If x, y and z are consecutive integers, and x < y < z, which of the [#permalink]
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07 Oct 2017, 00:59




Re: If x, y and z are consecutive integers, and x < y < z, which of the
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07 Oct 2017, 00:59






