PaulineEdwards Posts: 1, Reputation: 1 New Member #1 Sep 17, 2007, 06:43 PM
Formula for a sequence
What is the formula to find the number of one on one meetings a group of people
(let's say 10) will need to have to meet with every one else in the group.

I know that if there are 10 people, each of the 10 will need 9 meetings and each meeting will consist of 2 people. Therefore 45 meetings are necessary.

In the reverse, how do I find out how many people are meeting if it takes 66 meetings...
I know the answer is 12 by following the sequences. What is the formula?

HELP. Tks.
 ebaines Posts: 12,132, Reputation: 1307 Expert #2 Sep 18, 2007, 02:42 PM
You've got two data points already figured out. In both cases you took the number of people (let's call that N), multiplied it by (N-1), and divided by 2 to determine the number of meetings (call that M). So the formula is:

M = N*(N-1)/2, or M = (N^2-N)/2.

N^2 - N - 2M =0.

Now use the quadratic formula to solve for N.

 Question Tools Search this Question Search this Question: Advanced Search

## Check out some similar questions!

Mathematical sequence [ 8 Answers ]

What is the term I am looking for? 8? 1,1,2,3,5,____,13,21,34,.

Sequence series [ 2 Answers ]

What are the next 4 number in series 335, 443, 554,

What is the next number in this sequence? [ 1 Answers ]

1 1 3 2 4 6 5

Number sequence [ 2 Answers ]

What are the next three rows in the sequence: 1 11 21 1211 111221 312211 13112221

Can anyone solve this sequence? [ 1 Answers ]

OK so this isn't really homework or anything but I really can't work it out so.. :confused: 52 28 33 63 73 23 56... what's the next number?? Thanks, :D