What is the difference between the 64th and 65th triangular numbers?

Question

please help with explanantion thanks in advance

Answer 1

each triangular number is gotten by adding the next integer.
the first one is 1
the second one adds 2 to get 3
the third one adds 3 to get 6
the forth one adds 4 to get 10
and so on



so: the difference between the 2nd and 3rd is 3
the difference between the 3rd and 4th is 4
and the difference betwee th 64th and 65th is ..........

Answer 2

The answer from Paladin is very cute.

To get the answer without understanding anything, consider that the formula for the n-th triangular number is
T(n) =n(n + 1)/2. You need only compute T(65) - T(64).