I can't get the following question:
If xy + z = x(y+z), which of the following must be true
x=0 and z=0
x=1 and y=1
y=1 and z=0
x=1 or y=0
x=1 or z=0
Thanks for any help on this!
GMAT Prep Question
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As far as I am concerned it's Option E...
I.e. either x = 1 or z = 0
Lets take the first scenario when x = 1
xy + z = x (y + z)
xy + z = xy + xz
Therefore z would have to be equal to xz for the Equation to hold true
This is possible when x = 1 (Here xz = z since x is already 1)
Lets take the second scenario when z = 0
xy + z = x(y + z)
xy + z = xy + xz
xy + 0 = xy + 0
Hence it's option E
I.e. either x = 1 or z = 0
Lets take the first scenario when x = 1
xy + z = x (y + z)
xy + z = xy + xz
Therefore z would have to be equal to xz for the Equation to hold true
This is possible when x = 1 (Here xz = z since x is already 1)
Lets take the second scenario when z = 0
xy + z = x(y + z)
xy + z = xy + xz
xy + 0 = xy + 0
Hence it's option E
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For my point of view, there are 4 possible answers..
a) could be correct
x=0 and z=0
-> 0 = 0
b) could be correct
x=1 and y=1
-> 1 + z = 1 + z
c) could be correct
y=1 and z=0
-> x = x
b) wrong
x=1 or y=0
-> y+z = y + Z
-> z = xz
e) could be correct
x=1 or z=0
-> y+z = y+z
-> xy = xy
a) could be correct
x=0 and z=0
-> 0 = 0
b) could be correct
x=1 and y=1
-> 1 + z = 1 + z
c) could be correct
y=1 and z=0
-> x = x
b) wrong
x=1 or y=0
-> y+z = y + Z
-> z = xz
e) could be correct
x=1 or z=0
-> y+z = y+z
-> xy = xy
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dont simply put values of x y z in equation, Pratik.
solve it instead.
cybermusings approach is right 8)
solve it instead.
cybermusings approach is right 8)
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I'm sorry, I don't get cybermusings approach.
Is there another way to explain it?
Is there another way to explain it?
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Yes!
800GMAT!
Even cybermusings has "solved equation" like 800GMAT, I hope by now you understood how they approach the problem
800GMAT!
Even cybermusings has "solved equation" like 800GMAT, I hope by now you understood how they approach the problem
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I still don't get it..
OK, with z=0 or x=1 we have a solution.
But what about x=0 and z=0? Why isn't that true?
Thanks a lot!
OK, with z=0 or x=1 we have a solution.
But what about x=0 and z=0? Why isn't that true?
Thanks a lot!
- aim-wsc
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its a tricky one.
If you observe it closely u'll realise that y has no role here & therefore u should solve the equation first.
b/z u can play with numbers and substitute any damn value for ''y'' to make equation valid.patrik.herzog wrote:I still don't get it..
OK, with z=0 or x=1 we have a solution.
But what about x=0 and z=0? Why isn't that true?
If you observe it closely u'll realise that y has no role here & therefore u should solve the equation first.
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if x=0 & z=0 then I dont have explanation
where's Mark D?
where's Mark D?
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The question asks you what must be true
Is it always true that x=0 and z=0?
In other words, is x always 0 and z always 0
No
x can be 1
Since we are able to find another value for x besides 0
(1) does not hold
Is it always true that x=0 and z=0?
In other words, is x always 0 and z always 0
No
x can be 1
Since we are able to find another value for x besides 0
(1) does not hold
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bingo 8)
i've been loony lately
i've been loony lately
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