# Brain Teaser with Answer Unknown

1. Dec 19, 2005

### Tom McCurdy

I was looking through some old exams for my engineering class and uncovered the following question....

If you would like to know the answer please scroll down and highlight the text

But I don't have any clue how to get it. If anyone can figure it out that would be great... thx

-tom

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2. Dec 19, 2005

### TheStatutoryApe

Unfortunately I have never been very good at these sorts of problems so I don't really have anything else to offer.
---edit---
It looks like Greg may have changed the background colour.

3. Dec 19, 2005

### Tom McCurdy

Sorry it doesn't show on the old forum at least for me... I still have it set up for the old school view...

so far all i got is the difference between
8-13 is 5
13-28 is 15
and 28-8 is 20

working on this idea.

4. Dec 19, 2005

### Tom McCurdy

I have also found another thing that may help

the problem is 2 dimensional linear equations

5. Dec 20, 2005

### The Sphinx

y can't I see the question? :)

6. Dec 20, 2005

### Jimmy Snyder

If the equation is linear, then in my opinion, there is a typo in the question. Perhaps it should read:

Input A: {1, 0, 1, 1, ...}
Input B: {0, 1, 1, 10, ...}

Output: {8, 13, 28, 208, ... }

If this is the case, the linear equation is f = -7 + 15 * a + 20 * b. Then the inputs a = 10, b = 0 would produce the output f = -7 + 15 * 10 = 143. Since this is not one of the first 4 choices, the answer is E.