$$55\div7=7 \text{R}6$$. It is Saturday. 
My mom\textquotesingle s birthday is on Sunday, and my dad\textquotesingle s birthday is $$55$$ days after it. On what day of the week will my dad\textquotesingle s birthday be? ($$1999$$ Math Kangaroo Problem, Levels $$3-4$$, Question \#$$9$$) 
Options:
  - Sunday 
  - Monday 
  - Tuesday 
  - Thursday 
  - Saturday 