Re: Jokes and Riddles Centre
Quote:
Originally posted by Wardad:
1) key-in the first 3 digit of your phone number into the calculator
2) multiply by 80
3) then plus 1
4) multiply by 250
5) plus Last four digit of phone number
6) plus Last four digit of phone number again
7) minus 250
8) divide by 2 at Last
Is the answer your phone number???
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This will leave any positive integer x completely intact:
1) x div 10000
2) (1) * 80 = (x div 10000)*80
3) (2) + 1 = ((x div 10000)*80) + 1
4) (3) * 250 = (((x div 10000)*80) + 1) * 250 = 250*((x div 10000)*80) + 250 = 250*80*(x div 10000) + 250 = 20000*(x div 10000) + 250
5) (4) + x mod 10000 = 20000*(x div 10000) + 250 + (x mod 10000)
6) (5) + x mod 10000 = 20000*(x div 10000) + 250 + 2*(x mod 10000) = 2*10000*(x div 10000) + 2*(x mod 10000) + 250 = 2*10000*(x/10000) + 250 = 2*x + 250
7) (6) - 250 = 2*x + 250 - 250 = 2*x
8) (7) / 2 = 2*x/2 = x
It doesn't matter what number you start with....
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Of course, by the time I finish this post, it will already be obsolete. C'est la vie.
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