<p>I have been going through the practice tests in the blue book and I cant figure out how to do this problem:</p>
<p>A four digit integer, WXYZ, in which W,X,Y,and Z each represent a different digit, is formed according to the following rules:
1. X= W+Z+Y
2. W= Y+1
3. Z= W-5</p>
<p>What is the four digit integer?</p>
<p>If anyone knows how to do this please help!!</p>
<p>5940??? is it right??</p>
<p>YES! how’d you get it?</p>
<p>Start with rule #3: It means that W cannot be 0, 1, 2, 3, 4, or 5 and it means that Z cannot be 5, 6, 7, 8, or 9. (Because, for example, if Z was 5 then W would be 10, which is impossible).</p>
<p>Then move to rule #2: It means that Y cannot be 9. And because we know that W must be 5 more more, we also know that Y must be 4 or more.</p>
<p>So far, the possible values for W are 5, 6, 7, 8 or 9.
The possible values for Y are 4, 5, 6, 7, or 8.
The possible values for Z are 0, 1, 2, 3 or 4.</p>
<p>Now use rule #1 to calculate the lowest possible value for X. It is 9 (5+4+0). So, X must be 9.</p>
<p>Finally, there is only one combination of possible values for W, Y and Z that total 9, and they are 5, 4 and 0.</p>
<p>So, King is right!</p>
<p>look at it this way: Y cannot be anything less than 4, because if it is Z will be a negative number. Y also can’t be 5,6,7,8,9 because the X will be a two digit number which is impossible since it is one digit. So y can’t be 0,1,2,3,5,6,7,8,9 hmmm all that is left is 4. If Y is 4 then W=5 and Z is 0.
and since X=Y+Z+W then X=5.</p>
<p>then we get 5940 a number that fulfills all of the conditions of the question.</p>
<p>OMG thaank you so much! That makes sense now lol</p>
<p>i just saw that one in the blue book, the website has all the problems in it worked out so you should go to the satstudyguide.com website for solutions</p>