Problem - 4657
$\textbf{Snail in Well}$
At dawn on Monday, a snail falls into a $12$-inch deep well. During the day, it can climb up $3$ inches. However, during the night, it will fall back 2 inches. On what day can the snail finally manage to get out of the well?
$\textbf{Answer}$
The next Wednesday (or on the $10^{th}$ day).
$\textbf{Analysis}$
On the last day when the snail reaches the top, it can get out and will not fall $2$ inches during the night.
$\textbf{Note}$
A seemingly simple brain teaser always has a trap. The answer can not be as simple as $12\div (3-2)=12$.