# HandShakes Problem

Master of Golden Sun
Posers and Puzzles 12 Nov '03 15:57
1. 12 Nov '03 15:57
If there are 100 people from Hollywood at a party and each shakes the hand of every other person, how many handshakes take place?

1.) Total Handshakes = ________________________________________
Show all work here:

2.) What meathod did you use to solve this problem? You must use complete sentences.

Thanx. And You can thank me Lord Burn

-I am the master of Golden Sun no one can beat me not The Fusion Dragon not Deadbeard nobody. HA HA HA !
2. 12 Nov '03 21:452 edits
If there are 100 people from Hollywood at a party and each shakes the hand of every other person, how many handshakes take place?

1.) Total Handshakes = 100 x 100 - 100 = 9900 handshakes
Show all work here:

2.) What meathod did you use to solve this problem?
Just guessing: 100 people times 100 people minus themselves (because they won't shake their own hands). That's, of course, assuming that all the people in the room have all their limbs.
3. skeeter
515 + 30 days
12 Nov '03 22:551 edit
Originally posted by phisherman
If there are 100 people from Hollywood at a party and each shakes the hand of every other person, how many handshakes take place?

1.) Total Handshakes = 100 x 100 - 100 = 9900 handshakes
Show all work here:

2.) What meathod d ...[text shortened]... se, assuming that all the people in the room have all their limbs.
Wrong - assuming that every-one has two hands then it is 400 x 400 (left to right/left to left/right to right/right to left] minus 300{we are only able to shake withourselves just once) which equals 159,700 in total

skeeter
4. 12 Nov '03 23:201 edit

Person 1 shakes the hand of 99 others. Person 2 shakes the hand of 98 others, as he has already shaken the hand of person 1. Continuing with this pattern, the answer is the 99th triangular number.

Formula for triangular numbers = (1/2 x)(x-1)
Substitute 99 into the formula

49.5 * 98

which equals 4851. So 4851 handshakes take place.
5. royalchicken
CHAOS GHOST!!!
12 Nov '03 23:48
Er, 100 people each shake hands with 99 people, with two people per handshake. That's 9900/2 = 4950.

KFC Bognor is basically right, except he used the wrong TN. It should be 99+98+97+96+95+...+1 = (99^2 + 99)/2 = 4950.

6. skeeter
515 + 30 days
13 Nov '03 08:15
Originally posted by royalchicken
Er, 100 people each shake hands with 99 people, with two people per handshake. That's 9900/2 = 4950.

KFC Bognor is basically right, except he used the wrong TN. It should be 99+98+97+96+95+...+1 = (99^2 + 99)/2 = 4950.

Er, everyone is ignoring the fact that we can shake hands with another person in one of four ways - to wit :
1. Right to (their) right
2. Right to (their) left
3. Left to (their) left
4. Left to (their) right

and we can also shake hands with-ourselves. Once!

skeeter firmly esconced in the 159,700 camp.
7. Fiathahel
Artist in Drawing
13 Nov '03 14:011 edit
in full sentences:
Every body shakes everybody's hand, so everybody shakes 99 hands. If you sum that over all people you count every handshake twice. so therefor the answer is 100 * 99 / 2 = 4950
8. 13 Nov '03 16:26
Originally posted by Master of Golden Sun
[b]If there are 100 people from Hollywood at a party and each shakes the hand of every other person, how many handshakes take place?

What if everybody only shook hands with eachother once?
ðŸ˜µ
9. kingofthe303
Wormtongue
13 Nov '03 18:11
If there are 100 people from Hollywood at a party and each shakes the hand of every other person, how many handshakes take place?
More to the point, how many new film get made? ðŸ˜µ

I agree with RC the obvious answer is 4,950. But if each person shakes the hand of every other person, and assuming that every other person has two hands, the answer must be doubled. That is every person at the party shakes the left hand and the right hand of every other person = 9,900. It is irrelevant the number of combinations of shaking a right or a left hand because you only have to shake each hand once. The question also clearly states &quot;the hand of every OTHER person&quot;, so no need to include your left hand shaking your right hand in the calculation.
10. 13 Nov '03 20:08
Originally posted by kingofthe303
More to the point, how many new film get made? ðŸ˜µ

I agree with RC the obvious answer is 4,950. But if each person shakes the hand of every other person, and assuming that every other person has two hands, the answer must be doubled. That is every person at the party shakes the left hand and the right hand of every other person = 9,900. It is irreleva ...[text shortened]... HER person", so no need to include your left hand shaking your right hand in the calculation.
Of source &quot;Every other person&quot; might mean that each person only shakes with half of the other people....
11. 16 Nov '03 20:13
jeulious cezar, although a bit antisocial, and epileptic, was very good at parties, he would only show up for like an hour, but he would make a point of talking to _everyone_ there during that time, this is one of the reasons that he was so popular.

is the 99th triangle number the same as (99!)?
12. royalchicken
CHAOS GHOST!!!
16 Nov '03 21:451 edit
jeulious cezar, although a bit antisocial, and epileptic, was very good at parties, he would only show up for like an hour, but he would make a point of talking to _everyone_ there during that time, this is one of the reasons that he was so popular.

is the 99th triangle number the same as (99!)?
No, the 99th triangular number is the number of ways of selecting 2 items out of 100 things, with order of no consequence, or 99*100/2 = 4950.

99! = 99*98*97*96*95....*2 is very much larger.
13. 19 Nov '03 13:02
Hi! Times up on this fourm thanx to your help i was able to get the correct answer ðŸ˜€

If there are 100 people from Hollywood at a party and each shakes the hand of every other person, how many handshakes take place?

1.) Total Handshakes = 4950
Show all work here:

100 people each shake hands with 99 people, with two people per handshake. That's 9900/2 = 4950.

It should be 99+98+97+96+95+...+1 = (99^2 + 99)/2 = 4950.

2.) What method did you use to solve this problem? You must use complete sentences.

The method I used to solve this problem is that when I first approached this problem I tried to come up with an algebraic equation such as solving for x. Then I got the equation 99+98+97+96+95+...+1 = x where x would = 4950. Then I simplified my equation to (99^2 + 99)/2 = x. This is how I approached this problem, using a method where I was trying to solve for x.
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I am the Master of Golden Sun no one can beat me not Tempest Lizard, not Satrous and Mernardi, not Dullahun, not Star Magician, not Doom Dragon, and ecpcally not you! HA HA HA! ðŸ˜€
14. 19 Nov '03 17:35
I am the Master of Golden Sun no one can beat me not Tempest Lizard, not Satrous and Mernardi, not Dullahun, not Star Magician, not Doom Dragon, and ecpcally not you! HA HA HA! ðŸ˜€[/b]
Hey, you have some sintax error. you message should be:
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I am the Master of Golden Sun&lt;b&gt;,&lt;b&gt; no one can beat me&lt;b&gt;,&lt;b&gt; not Tempest Lizard, not Satrous and Mernardi, not Dullahun, not Star Magician, not Doom Dragon, and ecpcally not you! HA HA HA! ðŸ˜€[/b]
15. 19 Nov '03 17:36
The &lt;b&gt; blah &lt;b&gt; i did was to try to make it bold.
Oops, oh well.ðŸ˜›