Problem
COM-B1-M04-P001 Handshakes
#1
★☆☆☆☆ Level 1 of 5
In a room of \(10\) people, everyone shook hands with everyone else. How many handshakes occurred?
Count pairs of people.
Each handshake corresponds to a pair of people. There are \(10\cdot9/2=45\) pairs.
Basic pair-counting task.