Strongt wrote:18. w, x, y, and z are all positive integers. Which of the following proportions is NOT equivalent to the others?
a. y/w = z/x
b. z/y = x/w
c. w/y=x/z
d. w/z = x/y
e. x/w = z/y
i tried plugin' in numbers but didnt manage to get the answer...
answer is D
Perhaps you made an arithmetic error.
Let's plug in values that satisfy answer choice A.
A: y/w = z/x.
Let y=4, w=2, z=6, x=3.
4/2 = 6/3. This works.
Now let's plug these values into the remaining answer choices:
B: z/y = x/w.
6/4 = 3/2. This works.
C: w/y=x/z.
2/4 = 3/6. This works.
D: w/z = x/y.
2/6 = 3/4. Doesn't work.
The correct answer is
D.
For the skeptical, here's E:
E: x/w = z/y.
3/2 = 6/4. This works.
Cross-multiplying all the answer choices (as suggested by Ian) seems easier. But plugging in values is a perfectly valid approach.
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