Question

It was simran's first day at school that teacher suggested that it would be a good idea for each child to meet every other child in the class. the teacher said, "when you meet me shake hands and introduce yourself by name. " if there were seven children in the class how many total handshakes were there?

Answer 1

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There are seven children and a teacher
So The total number of handshakes are
$= 6 + 5 + 4 + 3 + 2 + 1 \\ = 21$
So Total handshakes are 28

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Answer 2

Hey there !!

→ Common sense :- We know that for a handshake,we need two people.

And, total number of people = 7.

Therefore, we need to select two people from a group of 7.

→ By Applying the concept of combinations, we get

Number of ways of selecting two children out of 7 = 7C2

7C2= 7!/(2! × 5!)=21

✔✔ Hence, number of handshakes=21 . ✅✅

THANKS

#BeBrainly.