Climbing The Mountain (BdMO Problem)
When Tanvir climbed a mountain, on his way to the top he saw it was raining times. At the mountain, on a rainy day, it rains either in the morning or in the afternoon; but it never rains twice in the same day.
On his way, Tanvir spent mornings and afternoons without rain.
How many days did it take for Tanvir to climb the mountain in total ?
The answer is 20.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
Suppose, Tanvir took n days to climb.
Then, there were 2 n period of times (mornings and afternoons) during his journey.
It rained 1 1 times. So, there was no rain in ( 2 n − 1 1 ) period of times.
Given that, there was no rain in 1 6 mornings and 1 3 afternoons or ( 1 6 + 1 3 ) = 2 9 period of times.
Now,
2 n − 1 1 = 2 9
⇒ n = 2 0