It would be for example: f-25
Since eleven is odd, there must be a centra element, which in this case is the sixth. So, we can write 11 consecutive integers as

Since the arithmetic mean is the sum of the values, divided by how many they are, we have

So, the mean of 11 consecutive integers is the 6th integer.
Option A is true because the sum of angles in a triangle is 180, so we can rule that one out immediately.
We can solve for x for the other 3 options by setting up this equation:
7x+2 + 4x+7 + 8x = 180 | Simplify
19x + 9 = 180 | Subtract 9
19x = 171 | Divide by 19
x=9
Now we can substitute x into all the values:
<J = 7x+2 = 65
<L = 4x+7 = 43
<K = 8x = 72
Looking at the options again, we can see that A, B, and D are true, leaving C to be false.