Answer: 40
Explanation
if you look at the number 4 it says it = 10
Then you look at 6 and it = 15
then you look at 8 and it = 20
SO everytime you add 2 it goes up 5.
So if you take the 8 and add 2 that's 10 and 10=25
So when you make your way to 16 it would be 40.