SOLUTION: During our vacation it rained on 13 days. Sometimes it rained in the morning, sometimes in the afternoon, but never at night. If it rained in the morning, the afternoon was clear.

Algebra.Com
Question 175456: During our vacation it rained on 13 days. Sometimes it rained in the morning, sometimes in the afternoon, but never at night. If it rained in the morning, the afternoon was clear. If it rained in the afternoon, the preceding morning was clear. We had 11 clear mornings and 12 clear afternoons. How long was the vacation??
Answer by Mathtut(3670)   (Show Source): You can put this solution on YOUR website!
if we add all the clear units(1/2days) with all the rain units(1/2days) and divide by 2 we should get the number of vacation days.
:
days
:
:
            1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
            **************************************************
Morning     C C R C C R R C C  R  R  C  C  C  R  C  C  R
            **************************************************
afternoon   R C C R C C C R C  C  C  R  R  C  C  R  C  C
            **************************************************

C=clear
R=Rain
RELATED QUESTIONS

Question: I had a flat tire after biking 3/4 of the way home. I walked the rest of the (answered by Mathtut,solver91311)
It rained on exactly 11 days during Jane’s holiday trip. On each rainy day it rained... (answered by Theo,richwmiller)
A student studying the weather for d days observed that 1) it rained on 7 days ,... (answered by richwmiller)
It rained 1/5 of the days during the month of April. How many days in April did it not... (answered by vleith)
Last year in Ferndale, CA, it rained on 28 days. What is the probability of rain on a day (answered by lynnlo)
The weather during the Smedleys' vacation was strange. It was cloudy on 13 different... (answered by edjones)
The weather during the Forburg's vacation was very strange. It was cloudy on 13... (answered by mducky2)
What solution do I need to solve this word problem? Of the 30 days in April last... (answered by Alan3354,Shin123)
Aisya is getting married tomorrow, at an outdoor ceremony in the desert. In recent... (answered by ikleyn)