There are ten kids in a class. When any two meet, each says "hi" to the other and the answer "hi" follows. Before the class starts, how many times would one hear the word "hi"?

Answer: 20

Step-by-step explanation:

From the question, there are ten kids in a class and when any two meet, each kid says "hi" to the other kid and the answer "hi" follows.

The number hi one would hear before the class starts would be 10 multiplied by 2 because there are 10kids and 2 hi whenever the kids greet.

= 10 * 2

= 20hi

There will be 20 times the word hi would be heard