A few friends decided to go on a vacation to a resort. It was raining heavily and it kept raining for thirteen days.

When it rained in the morning, the afternoon was beautiful and when it rained in the afternoon, the day was blessed with a clear morning.

Overall, the friends experienced eleven nice mornings and twelve nice afternoons. Can you find out the number of days they spent in the vacations ?

18

Let us solve this question by denoting variables.

Nice afternoons = P
Nice mornings = Q
No rain = R

Now, the number of days with rain = P + Q = 13
Days with clear mornings = Q + R = 11
Days with clear afternoons = P + R = 12

If we solve these three equations, we will get:
P = 7
Q = 6
R = 5

The total number of days = P + Q + R = 18