Here we have to count the number days from 3^rd February, 2012 to 18^th April 2012 ( both inclusive)
The given year is leap year, So February month has 29 days
From 3^rd to 29^th February = 27 days
In March = 31 days
From 1^st to 18^th April = 18 days
Total number of days = 27 + 31 + 18 = 76 days