There are 365 days.
All 12 months have "at least" 28 days. Only February has exactly 28 days, except in leap year.
There are 365.25 days in 12 months. So there are 365.25/12,*3 or 91.3125 days in 3 months
1 year =365 days =12 months 21 months =365 /12 X21 =638 or 639 days
365.25
all 12 months have 28 days wheather a leap year or no leap year. hope this helps, Elliexx
12 Months
12 966.0981 days
The riddle answer is "12" because all 12 months contain "at least" 28 days. February is the only month that has 28 days exactly, but 29 in a leap year.(The trick is that everyone says "1" because of this distinction. The version "If there are 7 months that have 31 days and 11 months that have 30 days, how many months have 28 days?" telegraphs the answer unless someone doesn't know how many months there are in total. So it is either erroneous or trivial.)
12 months exactly. There are always 12 months in a year of 365 days (366 in leap year)
11 of 12 months have at least 30 days
About 260
Technically all 12 months have at least 28 days in them. However, I suspect you are actually asking how many months have only 28 days. In that case, February is the only month to have only 28 days in its month (except for leap year when it has 29 days).