What is the value of (x-y)^4?
1. The product of x and y is 7
2. x and y are integers
Thanks
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What is the value of (x-y)^4
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alex.gellatly
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Anurag@Gurome
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(1) xy = 7alex.gellatly wrote:What is the value of (x-y)^4?
1. The product of x and y is 7
2. x and y are integers
Thanks
If x = 7, y = 1, then (x - y)^4 = (7 - 1)^4 = 6^4
If x = 14, y = 1/2, then (x - y)^4 = (14 - 1/2)^4 = (13.5)^4
No definite answer; NOT sufficient.
(2) x and y are integers.
x and y can take any values, so (x - y)^4 will have no definite answer; NOT sufficient.
Combining (1) and (2), x and y are integers such that xy = 7
So, the only possible value of x = 7 and y = 1 respectively; SUFFICIENT.
The correct answer is C.
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mcdesty
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Anurag@Gurome wrote:(1) xy = 7alex.gellatly wrote:What is the value of (x-y)^4?
1. The product of x and y is 7
2. x and y are integers
Thanks
If x = 7, y = 1, then (x - y)^4 = (7 - 1)^4 = 6^4
If x = 14, y = 1/2, then (x - y)^4 = (14 - 1/2)^4 = (13.5)^4
No definite answer; NOT sufficient.
(2) x and y are integers.
x and y can take any values, so (x - y)^4 will have no definite answer; NOT sufficient.
Combining (1) and (2), x and y are integers such that xy = 7
So, the only possible value of x = 7 and y = 1 respectively; SUFFICIENT.
The correct answer is C.
Well the answer is C but why can't X can be 1 and y 7?..
I know C still works because we are raising the difference to an even power which makes the sign of the base inconsequential.
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Anurag@Gurome
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You can take x = 1 and y = 7, that wouldn't change anything; x = 1, y = 7, then (x - y)^4 = (1 - 7)^4 = (-6)^4 = 6^4mcdesty wrote: Well the answer is C but why can't X can be 1 and y 7?..
I know C still works because we are raising the difference to an even power which makes the sign of the base inconsequential.
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mcdesty
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You are absolutely right sir..The only reason I brought it up was beacuse you said "The only possible value of x = 7 and y = 1"Anurag@Gurome wrote:You can take x = 1 and y = 7, that wouldn't change anything; x = 1, y = 7, then (x - y)^4 = (1 - 7)^4 = (-6)^4 = 6^4mcdesty wrote: Well the answer is C but why can't X can be 1 and y 7?..
I know C still works because we are raising the difference to an even power which makes the sign of the base inconsequential.
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vk_vinayak
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Correct. X and Y can be even -1 and -7, still the answer would be same, because the absolute difference between -1 an -7 is equivalent to absolute difference between 1 and 7.Anurag@Gurome wrote:You can take x = 1 and y = 7, that wouldn't change anything; x = 1, y = 7, then (x - y)^4 = (1 - 7)^4 = (-6)^4 = 6^4mcdesty wrote: Well the answer is C but why can't X can be 1 and y 7?..
I know C still works because we are raising the difference to an even power which makes the sign of the base inconsequential.
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mcdesty
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(-1-7) is -8 and that is 8 away from zero not 6...X and Y can't be -1 and -7...vk_vinayak wrote:Correct. X and Y can be even -1 and -7, still the answer would be same, because the absolute difference between -1 an -7 is equivalent to absolute difference between 1 and 7.Anurag@Gurome wrote:You can take x = 1 and y = 7, that wouldn't change anything; x = 1, y = 7, then (x - y)^4 = (1 - 7)^4 = (-6)^4 = 6^4mcdesty wrote: Well the answer is C but why can't X can be 1 and y 7?..
I know C still works because we are raising the difference to an even power which makes the sign of the base inconsequential.
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mcdesty
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"The absolute difference"...Must have read what he wrote poorly...Thkxeagleeye wrote:-1, -7mcdesty wrote:
(-1-7) is -8 and that is 8 away from zero not 6...X and Y can't be -1 and -7...
(-1) - (-7) = -1 + 7 = -6.
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alex.gellatly
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So on questions like these it is advisable NOT to factor it all out. I was tying a whole bunch of different algebraic things... all to no avail.Anurag@Gurome wrote:(1) xy = 7alex.gellatly wrote:What is the value of (x-y)^4?
1. The product of x and y is 7
2. x and y are integers
Thanks
If x = 7, y = 1, then (x - y)^4 = (7 - 1)^4 = 6^4
If x = 14, y = 1/2, then (x - y)^4 = (14 - 1/2)^4 = (13.5)^4
No definite answer; NOT sufficient.
(2) x and y are integers.
x and y can take any values, so (x - y)^4 will have no definite answer; NOT sufficient.
Combining (1) and (2), x and y are integers such that xy = 7
So, the only possible value of x = 7 and y = 1 respectively; SUFFICIENT.
The correct answer is C.
A useful website I found that has every quant OG video explanation:
https://www.beatthegmat.com/useful-websi ... tml#475231
https://www.beatthegmat.com/useful-websi ... tml#475231
