8 Explanation: The general formula for the number of handshakes is n(n-1)/2 where we have n people shaking hands with n-1 other people. so 28=n(n-1)/2 or 56=n^2-n the solution to this comes from solving n^2-n-56=0 so this factors as (x-8)(x+7) and the answer is 8 To understand this formula think of a small number, like 3 people Each person can shake hands with 2 other people. Let us call the people A, B, and C AB mean A shakes hand with B But AB=BA since if A shakes hands with B then B certainly shakes hands with A But if we look at all the possibilities we have AB, BA,BC, CB, AC and CA, as we explained this double counts so we divide by 2. 3(3-1)/2=3 as expected from the explanation above.
If six people meet there are fifteen handshakes.
There were ten people at the party. This is a triangular sequence starting with two people: 1, 3, 6, 10, 15, 21, 28, 36, 45, etc. There's an equation for this. With n people at the party, the number of handshakes is n(n-1)/2.
If there are n people who shake hands with each other exactly once, it can be observed that there are n x (n-1) handshakes. Since each handshake is counted twice here,we divide this by 2. Therefore, total number of handshakes is n(n-1)/2. In the given problem, Given: Total handshakes =66 i.e n(n-1)/2=66 n2-n =132 n2-n-132=0 (n-12)(n+11)=0 n =12 or n= -11 As handshakes cannot be negative we discard 11 . Therefore answer is , 12 people.
Everyone shakes hands with 4 other people. Since there are 5 people in the room this would suggest there are 5*4 = 20 handshakes. However, you would then be double counting handshakes: A shaking hands with B and B shaking hands with A is, in reality, only one handshake. Thus there are 5*4/2 = 10 handshakes in all.
38
There would have been 45 handshakes among 10 people at a meeting. This can be calculated using the formula n(n-1)/2, where n represents the number of people.
So, there will be 3 handshakes among the 3 people at the party.
If you multiply anything by 2 it always comes out even. So if people make 35 handshakes, we multiply it by 2 and we get 70 people. This will work with any different number of handshakes, odd or even.
Sixty-six unique, distinct handshakes.
If six people meet there are fifteen handshakes.
107 unique handshakes will be exchanged
There were ten people at the party. This is a triangular sequence starting with two people: 1, 3, 6, 10, 15, 21, 28, 36, 45, etc. There's an equation for this. With n people at the party, the number of handshakes is n(n-1)/2.
If there are n people who shake hands with each other exactly once, it can be observed that there are n x (n-1) handshakes. Since each handshake is counted twice here,we divide this by 2. Therefore, total number of handshakes is n(n-1)/2. In the given problem, Given: Total handshakes =66 i.e n(n-1)/2=66 n2-n =132 n2-n-132=0 (n-12)(n+11)=0 n =12 or n= -11 As handshakes cannot be negative we discard 11 . Therefore answer is , 12 people.
Everyone shakes hands with 4 other people. Since there are 5 people in the room this would suggest there are 5*4 = 20 handshakes. However, you would then be double counting handshakes: A shaking hands with B and B shaking hands with A is, in reality, only one handshake. Thus there are 5*4/2 = 10 handshakes in all.
4950 handshakes, that is the definite answer
38
1000*999/2 = 499500