For this case, we have the total of painters is 16, so to determine what percentage is painting the interior of the house, we make a rule of three:
16 ---------------> 100%
4 -----------------> x
Where "x" represents the% of painters who paint the interior of the house.
[tex]x = \frac {4 * 100} {16}\\x = 25[/tex]
Thus, 25% of painters are painting the interior of the house.
Answer:
25%