If w, x, and y are consecutive odd positive integers and w < x < y

w=2k+1
x=2k+3
y=2k+5

here k can be 0,1,2,3,4----

now y-x-w = 2k+5-2k-3-2k-1
=1-2k

we know that odd-odd-odd will always be odd. hence answer choices a,b and d are out. Also, maximum value of 1-2k is 1, when k=0. hence option E is also out. thus answer must be option C.

Hi All,

I mentioned earlier that this question could be approached with "brute force" - that's a concept that I haven't seen used too often on this site, so here's how to use that approach to get to the correct answer. Essentially, "brute force" in this case will involve TESTing VALUES until we get a solution that matches one of the 5 answer choices.

Since W, X and Y are CONSECUTIVE ODD POSITIVE INTEGERS and W < X < Y, we can start with the easiest set of values that comes to mind:

W = 1
X = 3
Y = 5

The question asks for what COULD be the value of Y - X - W.
In this case, the value would be...
5 - 3 - 1 = 1
+1 is NOT among the answer choices, so we have to keep working...

The next easiest set of values would be...
W = 3
X = 5
Y = 7

Here, Y - X - W is....
7 - 5 - 3 = -1

-1 IS among the answer choices, so we're done.

Final Answer:

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

Plug in some values for w < x < y

So, w < x < y = 3 < 5 < 7

Hence , y - x - w = 7 - 5 - 3 => -1

Answer will be -1

PS : This problem can be solved in less than 10 seconds if you plug in some values for this problem..

Option C

w, x & y are consecutive Positive Odd integers, such that w < x < y. Y - X - W = ?

Assume w = 2k + 1, then x = 2k + 3 & Y = 2k + 5. For k>=0.
Hence, Y - X - W = 2k + 5 - (2k + 3) - (2k + 1) = -2k + 1 = -1, -3, -5 , . . .

Thankyou.. Great explanation

1) Plug in any easy values satisfying the condition in the question:w,X,y are consecutive positive odd Integers and w<X<y

w=3,X=5,y=7

2) y-x-w=7-5-3=-1

3) option c


Manisha


Posted from my mobile device

1) Plug in any easy values satisfying the condition in the question:w,X,y are consecutive positive odd Integers and w<X<y

w=3,X=5,y=7

2) y-x-w=7-5-3=-1

3) option c

Posted from my mobile device

We see that x = w + 2, and y = w + 4; thus, y - x - w is:

w + 4 - (w + 2) - w = 2 - w

Since w is odd and positive, 2 - w must be odd and no greater than 1. The only answer choice that works is -1.

Answer: C

\(\left\{ \matrix{\\
w = 2M - 1 \hfill \cr \\
x = 2M + 1 \hfill \cr \\
y = 2M + 3 \hfill \cr} \right.\,\,\,\,\,\,\,\left( {M \ge 1\,\,{\mathop{\rm int}} } \right)\)

\(? = y - x - w = - 2M + 3\,\,\,\,\,\,\,\,\,\mathop \Rightarrow \limits^{{\rm{alternatives!}}} \,\,\,\, - 1\,\,\,\,\,\,\,\left( {{\rm{when}}\,\,M = 2} \right)\)


This solution follows the notations and rationale taught in the GMATH method.

Regards,
Fabio.

We can work out trial and error method.. 3 numbers in seq from 1,3,5,7,9,11

5-3-1 = 1
7-5-3= -1
9-7-5=-3
11-9-7=-5

The answer is -1..