In the given statement, it is assumed that we know the definition of a leap year which is a year in the Gregorian calendar, occurring every 4 years, containing366 days with February 29 as the extra day. Assumption I: February will have 29 days in 2020. This assumption is implicit as in a leap year in the month of February there are 29 days. Assumption II: The year 2017 is not a leap year. Since every 4th year is a leap year, so by dividing the year by 4, we can determine if the given year is a leap year or not. Since 2017 is not divisible by 4, we cansay that 2017 is not a leap year. Hence, both assumptions 1 and 2 are implicit.