Journal of the Mathematics Council of the Alberta Teachers’ Association
Volume 48 Issue 1, December 2010
3
Kevin Wang
On a full-sized piano, there are 88 keys. Many different combinations of keys can be pressed, and hence many sounds can be made. For example, a one-keyed piano can make one sound. A piano with two keys can make three possible sounds from pressing the keys: two at the same time, key number one and key number two. A piano with three keys can make seven sounds. Thus, on a full-sized piano with 88 keys, how many different sounds can be made?
