How many times do three children exchange phones? Three children send messages to each other. How many short messages do you need to send * * *?

Children's ABC (the letter in front is the sender, for example, AB is A, call B and send a message)

There are three kinds of telephones, AB, BC and AC. Because a calls B and B and calls a at the same time, three times is enough.

There are six kinds of short messages, AB, BA, AC, CA, BC and CB. Sending messages to each other, then A sends messages to B and B and sends messages to A separately, which is different, so there are six kinds. Other reasons are the same. Understand? hope this helps