Description

This article is from the Mensa FAQ, by Phil Hill phil@miracle.com with numerous contributions by others.

16 What is the Mensa test like? Commentary on the Questions and Answers

QUESTION #2 (Sally and her favorite numbers)

The answer that Sally likes perfect squares is the answer that the
question writer was "looking" for. Mensans always like to bend the
rules a little, and find other solutions that give you the correct
answer:

* Sally likes numbers whose sum of the digits is odd. Therefore she
likes 1600, not 1700.

Or other solutions that give the incorrect answer:

* Sally likes numbers in which the sum of the digits plus the number of
digits equals 12. Therefore, she likes 225, 900, 144, and, of course,
1700.

* Sally clearly likes the zeros of:
x^4 + 404 * x^3 - 1792800 * x^2 + 32790000 * x - 49572000000
so the numbers she likes are 144, 225, 900, and 1700.

Or even solutions that prove that neither answer is correct:

* Sally does *not* like 1600 or 1700, because neither number has digits
which sum to 9. She *does*, however, like 1800.

QUESTION # 4 (Insert +/1 to make total equal one)

When many Mensans look at the answer and see "There are probably other
solutions, so if yours is correct, give yourself full credit", they
usually wonder how many solutions there are. How many can you find?

Still not challenged enough? Let's bend the rules a little bit, the
question doesn't state that we *have* to put a sign between every pair
of numbers. Adjacent digits would therefore form a number. For
example:

0 1-2 3+4 5+6 7-8 9 = 1 (01-23+45+67-89 = 1)

How many more can you find?

- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -

* ANSWERS TO COMMENTS *
QUESTION #4, Part One

0+1+2+3+4-5+6+7-8-9 | 0-1+2+3-4+5+6+7-8-9 | 0+1-2-3+4+5+6+7-8-9
0+1+2+3+4+5-6-7+8-9 | 0-1+2+3+4-5+6-7+8-9 | 0+1-2+3-4+5+6-7+8-9
0-1-2-3+4+5+6-7+8-9 | 0+1-2+3+4-5-6+7+8-9 | 0+1+2-3-4+5-6+7+8-9
0-1-2+3-4+5-6+7+8-9 | 0-1+2-3-4-5+6+7+8-9 | 0-1+2+3+4+5-6-7-8+9
0+1-2+3+4-5+6-7-8+9 | 0+1+2-3-4+5+6-7-8+9 | 0-1-2+3-4+5+6-7-8+9
0+1+2-3+4-5-6+7-8+9 | 0-1-2+3+4-5-6+7-8+9 | 0-1+2-3-4+5-6+7-8+9
0+1-2-3-4-5+6+7-8+9 | 0+1+2+3-4-5-6-7+8+9 | 0-1+2-3+4-5-6-7+8+9
0+1-2-3-4+5-6-7+8+9 | 0-1-2-3-4-5+6-7+8+9
 
QUESTION #4, Part Two
0 1-2 3+4 5+6 7-8 9 | 0+1-2 3+4 5+6 7-8 9 | 0 1+2 3+4-5+6 7-8 9
0+1+2 3+4-5+6 7-8 9 | 0-1+2 3-4+5+6 7-8 9 | 0 1+2 3-4 5-6 7+8 9
0+1+2 3-4 5-6 7+8 9 | 0 1-2 3-4+5-6 7+8 9 | 0+1-2 3-4+5-6 7+8 9
0 1-2-3-4 5+6 7-8-9 | 0+1-2-3-4 5+6 7-8-9 | 0 1+2-3 4+5 6-7-8-9
0+1+2-3 4+5 6-7-8-9 | 0-1+2 3+4+5-6-7-8-9 | 0-1 2+3 4-5-6+7-8-9
0 1+2+3+4-5+6+7-8-9 | 0 1-2-3+4+5+6+7-8-9 | 0 1+2 3+4 5-6 7+8-9
0+1+2 3+4 5-6 7+8-9 | 0 1+2 3-4-5-6-7+8-9 | 0+1+2 3-4-5-6-7+8-9
0 1+2+3+4+5-6-7+8-9 | 0 1-2+3-4+5+6-7+8-9 | 0 1-2+3+4-5-6+7+8-9
0 1+2-3-4+5-6+7+8-9 | 0-1+2 3+4 5-6 7-8+9 | 0 1-2 3-4 5+6 7-8+9
0+1-2 3-4 5+6 7-8+9 | 0-1+2 3-4-5-6-7-8+9 | 0 1-2+3+4-5+6-7-8+9
0 1+2-3-4+5+6-7-8+9 | 0 1+2-3+4-5-6+7-8+9 | 0 1-2-3-4-5+6+7-8+9
0 1-2 3+4+5+6+7-8+9 | 0+1-2 3+4+5+6+7-8+9 | 0 1+2+3+4 5-6 7+8+9
0+1+2+3+4 5-6 7+8+9 | 0 1 2+3 4+5-6 7+8+9 | 0+1 2+3 4+5-6 7+8+9
0 1+2+3-4-5-6-7+8+9 | 0 1-2-3-4+5-6-7+8+9 | 0-1-2 3+4+5+6-7+8+9
0 1-2+3 4-5 6+7+8+9 | 0+1-2+3 4-5 6+7+8+9 | 0 1 2-3 4+5-6+7+8+9
0+1 2-3 4+5-6+7+8+9

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