First find the total number of pieces of candy Anna gets: 14 pieces/house * 60 houses = 840 pieces
Then find the total number of pieces of candy Billy gets: 11 pieces/house * 75 houses = <<11*75=825>>825 pieces
Then subtract the number of pieces Billy gets from the number Anna gets to find the difference: 840 pieces - 825 pieces = <<840-825=15>>15 pieces
#### 15