Question

Is the number even or odd?
2018−2017+2016−2015 + . . . +2–1

Answer 1

It is the odd number 1009

Explanation:

Notice that this problem involves the addition of a number "1" per consecutive pair (a number minus the integer that immediately precedes it), so it adds "1" (one) every couple of consecutive numbers.

2018 - 2017 = 1

2016 - 2015 = 1

...

4- 3 = 1

2 - 1 = 1

That means it is the addition of 2018/2 = 1009 numbers "1". This clearly results on the number 1009, which is an odd number.