Size got it right because it’s multiplied by 100
D. Because you're multiplying 3 by a number which is what the variable represents (n), then you're just adding 7 to that which equals 19 all together. It all translates to 3n+7=19.
Whatever% of anything is just (whatever/100) * anything.
thus 29.5% of something, is just (29.5/100) * something, and the decimal form of 29.5% is just 29.5/100 or the quotient of 29.5÷100.
ANSWER

EXPLANATION
Given;

The standard equation of circle of a circle centered at (h,k) with radius r is;

Re-write the given equation in the standard form, we have;

Hence, h=-3, k=-5, radius is 4
V = sqrt (64h)
V = sqrt (64 * 23)
V = sqrt 1472
V = 38.366 rounds to 38.37 ft <==