\(\because\) \(\cfrac{1900}4\) = 475
\(\because\) 1900 is completely divisible by 4.
\(\therefore\) 1900 is a leap year
\(\therefore\) Number of days from 21 February of year 1900 is 29
= 9 days of February + 31 days of March + 30 days of April + 31 days of May + 4 days of June
= 9 + 31 + 30 + 31 + 4 = 105 days
