The equation: s=p2−p2 gives the number of handshakes, s, that would take place when p people gather in a room and every person in the room shakes the hand of every other person exactly once. A) There are 12 people in the room, how many unique handshakes will there be? Answer: There will be unique handshakes. B) If there are 120 unique handshakes in the room, how many people are there? Answer: There are people in the room.