40th day = 39th day after first day joining.  39 days/7 = 5 weeks R 4 days. 4 days after Tues is Saturday. 
Alice\textquotesingle s first day in Caterpillar Club was Tuesday. She wants to throw a party on her 40th day in the club. If Alice attends the club everyday, on which day of the week will the party be? 

- Friday 
- Saturday 
- Sunday 
- Monday 
- None of the above 