A basket of fruit contains 3 dozen apples. If about 11.11% of the apples are rotten, how many apples are rotten? Round your answer to the nearest whole number.

3 dozen is equal to 3 x 12 = <<3*12=36>>36 apples.

11.11% of 36 is equal to 36 x 11.11/100 = <<36*11.11/100=3.996>>3.996 apples.
So, 4 apples are rotten. Answer: \boxed{4}.