Except the last day, the snail could climb up $2-1=1$ m. Thus, it takes the snail $(10-2)\div1+1=9$ days to get out of the well. $9$ days from Monday is the next Tuesday. 
On Monday morning, a snail fell down a well which is $$10$$ meters deep. During the day, it climbs up $$2$$ meters, and during the night it slides down $$1$$ meter. On what day of the week will the snail get out of the well? ($$1998$$ Math kangaroo Problem, Level $$5-6$$, Question \#$$18$$) 
- $$$$Tuesday 
- $$$$Thursday 
- $$$$Saturday 
- $$$$Sunday 
- $$$$Monday 