Math Challenge...?

Question

You have just won laser tag with a huge group of 39 friends. You declare that everyone, including yourself, needs to shake hands with every player so that no feelings are hurt. How many total handshakes will be made with your group?

Answer 1

You are going to make 39 handshakes. Friend number 1 is going to make 38 (cos he already shook hands with you), Friend 2 makes 37... etc etc.

Add them all up. You can do this quickly by using the formula

x * x+1 / 2

I.e. 39 * 40 / 2
= 780

Answer 2

The proper equasion is (x-1 )+(x-2)+(x-3) and so on till (x-x) doing this gives you a total of 726 . Most people don't realize that the last guy has already shaken everyones hand And you don't shake your own so x is one less than the total number of people.

Answer 3

39 + 38 + 37 + ...+ 3 + 2 + 1

I will leave the math to you.

Answer 4

SUM from 1 to 39 of X = 39+38+37... = (39)(40)/2 hanshakes

Answer 5

16(38+1)
16(39)
634

Answer 6

every one will make 38 hand shakes because there are 39 of u and u r not going to shake hand with yourself

Answer 7

39*38

Answer 8

38+37+37+.............
cuz first person shakes hand with 38 ppl
then the next person shakes hand with one less

Answer 9

if everyone shook hands once....including yourself would be 40 . that would be 40 hand shakes. That's if everone shook hands only once

Answer 10

Here is your answer:
http://mathforum.org/library/drmath/view/56219.html