100 computers "techies" come to a conference. Each of them exchanges a business card with each of the others.
How many cards are exchanged?
2006-11-25 08:55:29 · 10 answers · asked by Han Tran 2 in Science & Mathematics ➔ Mathematics
OOHHH! OHHH!!! I KNOW THE ANSWER TO THIS!!! ok, there is an equation for this, it's n(n-1)/2.
So, if there are 100 "techies" then put 100 into the equation.
100(100-1)/2------the equation
100(99)/2------simplified
9900/2------- 100*99
4950-----THE ANSWER!!!
So, there would be 4950 cards exchanged!
THIS IS THE ANSWER, I PROMISE YOU!
2006-11-25 09:14:47 · answer #1 · answered by Glitterz23 2 · 0⤊ 0⤋
The first techy exchanges card with 99 others. So 198 cards are
exchanged. The second techy only exchanges with 98 others
'cuz he/she already exchanged with the first guy, so 196 more
cards are exchanged. In the techy world, women are guys too. The third guy exchanges with 97 'cuz he/she has already exchanged with the first 2 guys, so 194 cards are now exchanged. The last guy doesn't have to exchange with anyone
'cuz every one else has exchanged with him/her. The second to the last only had to exchange with one other, so that was 2 cards
on the last exchange. Now we have
198+196+194+...+2=
2(99+98+97+...+1)=
2((99+1)+(98+2)+(97+3)+...
+(51+49)+50)=
2(4950)= 9900 cards
2006-11-25 09:14:15 · answer #2 · answered by albert 5 · 0⤊ 0⤋
That would be 4950. NOT 9900, because that would mean that say. technic #1 had exchanged a card with technic #2, and then thechnic #2 exchanged a card with tech #1, so each of them would have two cards of the other guy. That is counted according to an equation you will find in sources. Nvm you don't understand the text around, what is important is the equation itself, and as it is maths, it's universal language, and you will get it ;)
2006-11-25 09:08:07 · answer #3 · answered by enthernae 2 · 0⤊ 0⤋
Each of the 100 techies exchanges a card with each of the other 99 techies.
The total number of cards exchanged is 100 x 99 = 9,900.
2006-11-25 08:59:11 · answer #4 · answered by Jim Burnell 6 · 0⤊ 1⤋
100 x 99 = 9900
2006-11-25 09:04:46 · answer #5 · answered by lemon drops 3 · 0⤊ 0⤋
100 people hand out 99 cards = 9900 cards
2006-11-25 09:00:52 · answer #6 · answered by natrgrrl 2 · 1⤊ 0⤋
100*99= 9900
2006-11-25 09:00:00 · answer #7 · answered by Anonymous · 1⤊ 0⤋
99+98+97+96....+1=4950
2006-11-25 08:58:47 · answer #8 · answered by Zack C 3 · 0⤊ 1⤋
9900
2006-11-25 09:49:58 · answer #9 · answered by Salem O 1 · 0⤊ 0⤋
9900-----DON'T ASK IM A SEVENTH GRADER IN CALCULUS
2006-11-25 08:58:34 · answer #10 · answered by Anonymous · 2⤊ 0⤋