Math question please help!?

Its been a long time since I've done this and I'm not sure, but they way I did it is... there are 18 out of 36 people in wood working, 18 over 36 reduces to one-half, there are 12 people out of 36 taking photo, 12 over 36 reduces to one-thirds, and 6 out of 36 taking metal, 6 over 36 reduces to one-sixth. Not sure if this is right, but maybe it helps?