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?
(In reply to
Linear algebra solution by Jer)
The methodology can be considerably shortened.
From the system of equations:
(1) A+B = 100; (2) B+C=95; (3) A+C=19
Just add (1), (2), and (3) and divide by 2 to obtain:
A+B+C= 107
Edited on October 13, 2022, 6:09 am
re: Linear algebra solution
