Trivia--Think of a Number

[Gregory Matthews]

If you have a need to stump someone, tell them that you will demonstrate that you can read their thoughts.  Tell them to pick in their mind, and keep silent about it, one number in the series that begins with zero and ends with seven.  Tell them that by asking you three simple questions your can determine the number that they picked.  Those three questions are:  Is the number that you picked in the following series:

a)  1, 3, 5, 7          A yes answer to this question gives a numerical value of 1.

'b)  2, 3, 6, 7          A yes answer to this question gives a numerical value of 2.

c)  4, 5, 6, 7            A yes answer to this question gives a numerical value of 4

All "no" answers give a numerical value of zero.

Add up the numerical value of the three questions and you will have the number that the person was  thinking about.

NOTE:  The above is something that I have adapted from a published work of the Scientific American more than 50 years ago.

Or try this one:

1)  Write a 3-digit number, using any three digits,  Numbers can repeat.  E.G  334

2) Now write a 6-digit number by repeating the above number, in the same order.   E.G. 334,334

3)  Now divide that 6-digit number by 7.   E.G.  47,762.

4)  Now divide that number by 11.  E.G.  4,342.

5)  Now divide that number by 13.  E.G.  334.

NOTE:  Further investigate change the order of division.  E.G. Divide by 11, then 7 and then 13.  How will this change the final answer?