During a certain period of days in Cucumberland recently it was observed that when it rained in the afternoon, it had been clear in the morning, and when it rained in the morning, it was clear in the afternoon. (In a given morning or afternoon, it is either raining or it is clear.) It rained on 100 days, and was clear on 19 afternoons and 95 mornings. How many days were there altogether?
100 days of rain forces some combination of 100 clear mornings or afternoons. This leaves 14 unaccounted half-days of clearness, half-days that must come in pairs, as there is no rain on these days. Thus 7 clear days. A total of 107 days :-)
Posted by owl
on 2004-11-02 13:38:17