109. Four People Meet in a Room. Each Person Shakes Hands
Four people meet in a room. Each person shakes hands once with each other person.
How many hand shakes are there in all?
Submitted by tartle · Added 4 December 2010
Solution:
In a group of four people, each person shakes hands with three others. Since each handshake involves two people, the total number of unique handshakes can be calculated using the formula n(n-1)/2, where n is the number of people. Thus, the total number of handshakes is 4(4-1)/2 = 6.
Comments (17)
:) THE ANSWER IS 10
The answer is 6.
the answer is 12...
ex: there is guy 1,2,3, and 4
guy one shakes hands with:
1-2, 1-3, 1-4
thats 3 hand shakes
continue with guy 2,3, and 4. or do 3 times 4. either way you find 12
I agree with wesmode. The answer is 6
The answer is 6.
For those who have heard of Combinations and Permutaions, the answer 4C2.
6 only,
1st person hand shakes with 2,3,4 is equal to 3 handshakes
2nd person hand shakes with 3,4 is equal to 2 handshakes
3rd person hand shakes with 4 is equal to 1 handshake
4th person has already shook hands with all of them, so a total of 6
i agree with einsteinager!
I agree with wesmode & einsteinager. The answer is 6.
if 4 persons are A,B,C,D
They will shakes their hands with each person like
AB, AC, AD, BC, BD, & CD
So if is mote than 6 time then it would be doubled.
the answer is absolutely 12.
it's sure.....6
People the answer is 6.
Here's a clear explanation.
There are 4 people namely A B C D.
A shakes hand with B C D.
B shakes hand with C D. (B has already shook hands with A in the line above so he won't do it again)
C shakes hand with D.
It's essential to remember that everyone shakes hands with others only once. So AB is the same as BA.
I hope it's clear.
If not I'll be happy to answer any query.
there will be 6
exactly 6 times
like the 2014 world cup, each group has 4 teams and each team played 6 times to complete the first round game!
Well, if you made an undirected graph the answer would be: (n*(n-1))/2
And that is (4*3)/2 that is 12/2 which is 6.
Explanation(wikipedia): Undirected graph:
An undirected graph is one in which edges have no orientation. The edge (a, b) is identical to the edge (b, a), i.e., they are not ordered pairs, but sets {u, v} (or 2-multisets) of vertices. The maximum number of edges in an undirected graph without a self-loop is n(n - 1)/2.
https://imagizer.imageshack.us/v2/202x136q90/631/mhA5sJ.png
sure 6 is the ans.....
The answer is 6
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