The blind man and the four pills

Question

A blind man must take exactly one red pill and one blue pill every day, or he will die. The pills are identical in size, shape, weight and texture; only their colour differs. One day he drops two red pills and two blue pills on the table and cannot tell which is which. He has no more pills and nobody to ask. How does he take exactly one red and one blue today, and again tomorrow?

Accepted Answer

He cuts each of the four pills in half, keeping the halves of each pill separate. Then he takes one half of every pill: that is two red halves and two blue halves, exactly one red pill's worth and one blue pill's worth. Tomorrow he takes the other four halves. Why it works. Whatever the colours are, the four pills contain two reds and two blues. Half of each pill, taken together, contains half of all the red (one red pill's worth) and half of all the blue (one blue pill's worth). He never needs to know which pill is which. The general idea. When you cannot tell items apart but you know the to…

The blind man and the four pills

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