If k > 0, x + k = y, and y + 3k = z, what is the ratio betwe

Hi,

From the answer, I could only assume that "z � x" is z-x.
So, (z-x)/(y-x) = 4k/k = 4:1
thus (E)

Regards,

If k > 0, x + k = y, and y + 3k = z, what is the ratio between z � x and y � x ?

(A) 1 to 4
(B) 1 to 2
(C) 2 to 1
(D) 3 to 1
(E) 4 to 1


Picking numbers is probably the fastest solution to solve this problem. First, k>0 = k could be ANY positive number. For the purposes of the explanation K= 2. x + 2 = y and y + 3(2) = z. Rearrange the latter equation as to isolate y.

X + 2 = Y
Z - 6 = Y

Now pick Any number for Y. For the sake of our example Y will be 10. Now the equation looks like:

X + 2 = 10
Z - 6 = 10

Solve for X. Solve for Z. X= 8 and Z = 16

what is the ratio between z � x and y � x
16 to 8 as 10 to 8
8 2
8/2 = 4 2/2=1

Thus answer choice E is correct- 4 to 1.
Kudos please

Could you please elaborate on how you got 8 2 and further?
thanks

16 - 8 = 8

10 - 8 = 2

I hope this is helpful now. Lol (I'm being a troll). Thanks

Assuming that the required ratio is (z - x)/(y - x),

x + k = y
y - x = k

y + 3k = z
x + k + 3k = z
z - x = 4k

(z - x)/(y - x) = 4/1

(z-x )/ (y-x) == (y + 3k -x )/ (y-x) where k = y-x

hence == (y-x) + 3(y-x) / ( y-x) = 4(y-x)/(y-x) == 4/1 !!

Hi All,

This question is perfect for TESTing VALUES.

We're given 3 "rules" that we have to follow (regarding the values we choose to TEST):
1) K > 0
2) X + K = Y
3) Y + 3K = Z

Let's keep the values small:
X = 1
K = 2
1 + 2 = 3 = Y

3 + 3(2) = 9 = Z

The question asks for the ratio of (Z-X) to (Y-X). Using the values we chose....

(9-1) to (3-1) = 8 to 2 = 4 to 1

Final Answer:

GMAT assassins aren't born, they're made,
Rich

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