Bunuel wrote:
LM wrote:
If x, y, and z are positive integers, x is a factor of 2y, and 3y is a factor of z, which of the following must also be an integer?
A) \(\frac{y}{x}\)
B) \(\frac{2y}{6}\)
C) \(\frac{xy}{3z}\)
D) \(\frac{zx}{3y}\)
E) \(\frac{zy}{3x}\)
\(x\) is a factor of \(2y\), means that \(\frac{2y}{x}=integer\).
Similarly, \(3y\) is a factor of \(z\), means that \(\frac{z}{3y}=integer\). Multiply both sides of this equation by integer \(x\): \(\frac{z}{3y}*x=integer*x\) --> \(\frac{zx}{3y}=x*integer=integer*integer=integer\).
Answer: D.
Hope it's clear.
Hello Bunuel,
Can we simplify the options and then attempt the Questions
For Option 5, ZY/3X can be simplified as 3Y*Y/3X --> Y*Y/X which may or may not be true.
For example looking at option 4, ZX/3Y, if simplify it as ---> Z=3y and then the eqn becomes 3y*y/ 3y which gives x only
Please confirm
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