Below is a copy of a calendar for July 2015.
Statement: The sum of any two adjacent dates is always an even number. (Example of adjacent dates: 1 and 8, 22 and 29 etc)
(Do it algebraically and check if the given statement is true or false)
Let us consider any two adjacent dates.
If we take the first number which is as 'x', then number adjacent to this will be 'x + 7'.
Then the sum is
(x) + (x + 7) = 2x + 7
We note that 2x is a multiple of 2 and hence always an even number. When 7 is added to an even number, we get an odd number.
Hence the sum of any two adjacent dates in a calender is always an odd number.
Therefore the given statement is false.