omitted 
A worm is staying at the bottom of a well with a depth of $$10$$ metres. If it climbs up $$3$$ metres in the daytime and slips down $$2$$ metres at night, which day will it climb up to the ground? 
Options:
(1) The $$6$$th day 
(2) The $$7$$th day 
(3) The $$8$$th day 
(4) The $$9$$th day 