One answer could be 2 as 2^2 is 4 and 2+2 also equals 4
If the interest rate is compounded daily, we have the effective interest rate calculated as:
r = (1 + 0.1022/30)^30 -1
r = 0.1074 or 10.74%
Therefore, the effective interest rate if the compounded daily rather than monthly is 10.74-10.22 = 0.52 points higher.
Let x represent the length of the side of the pen that is parallel to the barn. Then the area (y) will be
.. y = x(300 -x)/2
This describes a downward opening parabola with zeros at x=0 and x=300. The vertex (maximum) will be found at the value of x that is halfway between those, x = 150.
For that value of x, the pen area is
.. y = 150(300 -150)/2 = 150^2/2 = 11,250 . . . . . square feet.