Quote:
Originally Posted by zelda_pinwheel
this puzzle is hurting my brain. i am not sure i am even close (since at first i thought the opposite, but upon re-reading i realised i had probably misunderstood one detail of the puzzle) but i will try it anyway...
Spoiler:
i think the last bean should be white.
the reason is, whatever the draws, the number of white beans can only be reduced by 2 at a time, but black beans are removed 1 at a time. we start with an odd number of white beans. since it's impossible to divide an odd number by 2, there will be 1 white bean left over.
the results of possible draws is this :
2 black beans : end result, 1 less black bean in the pot, same number of white beans (one put on the pile, other back in the pot)
2 white beans : end result, 2 fewer white beans in the pot but 1 more black bean (both white beans discarded, one black from the pile put in)
1 black, 1 white : end result, 1 less black bean, same number of white beans (black one on the pile, other (white) bean back in the pot)
i've changed my mind about 5 times about my answer so i am now going to go see what other people have replied.  |
Well done Zelda, exactly right and for the right reasons.