The pieces of a 500 piece puzzle are stored in three containers. 220 pieces are in the first contain

The pieces of a 500 piece puzzle are stored in three containers. 220 pieces are in the first container and 180 pieces are in the second container. What percentage of the pieces is in the third container?

Calculate the number of pieces in the 3rd container:
Pieces in container 3 = Total Puzzle Pieces - Pieces in container 2 - Pieces in container 1
Pieces in container 3 = 500 - 220 - 180
Pieces in container 3 = 100

Calculate the percentage of pieces in the 3rd container:
Percentage of pieces in container 3 = 100% * Pieces in container 3 / Total puzzle pieces
Percentage of pieces in container 3 = 100% * 100 / 500
Percentage of pieces in container 3 = 100% * 0.2
Percentage of pieces in container 3 = 20%