What is the solution to this brain teaser?

Factual Questions
1

What number should replace the question mark?

2

17/4?

3

5

Start at “2” and go clockwise. The difference between each two numbers is 1, 2, 3, 4, 5

2+1 = 3
3+2 = 5
5+3 = 8
8+4 = 12
12+5 = 17

4

The new number is 5.

The starting number is 2 (on the lower left) You progressively add one more to the previous number and take the new result as input into the next equation.

So, you start with 2, add 1 to get 3. You take the new numer (3) add 1+1 (2) to get 5. You take the new number (5), add 2+1(3) to get the new number 8. Etc.

1+2=3
2+3=5
3+5=8
4+8=12
5+12=17