Answer:
The worm will take 10 days to get to the top of the wall.
Step-by-step explanation:
Worm is at the bottom of a 12 foot wall.
Worm crawls up the distance = 3 feet per day
and slips down the distance = 2 feet per day
Everyday it crawls up by the distance = 3 - 2 = 1 feet
Time taken to crawl up to the height 9 feet = 9 days [ Since it crawls up 1 feet per day]
Remaining distance after 9 days = 12 - 9 = 3 feet
Now on the 10th day worm will crawl up by 3 feet of the distance remaining.
Hence the worm will take 10 days to get to the top of the wall.
