The easiest way to do this is using and algebraic equation. First, 43% is equal to the decimal .43.
Multiplying the total number by the percentage gives you the answer, so
Let x = the number you're looking for.
X * .43 = 16
X = 16 / .43
X = 37.20930232558
Now, I'm assuming you're allowed to round so
37.2093
