A calendar only has 4 days in a week; Sunday, Monday, Tuesday and Wednesday in that order. Also, it has 10 months. 1st month has 1 day, 2nd month has 2 days, 3rd month has 3 days and so on If, according to the calendar, 01/01/100 is a Sunday, what day will be 02/02/200?

I need help in understanding this