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The first person can be selected in one of seven ways. Having selected him, the second can be selected from the remaining six in six ways. So there would appear to be 7*6 ways of selecting the couples shaking hands.
But, x shaking y's hand is the same handshake as y shaking x's hand. Thus each handshake is conted twice, So the total number of handshakes is 7*6/2 = 21
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Seven people shake hands once how many times do they shake hands?
For everyone to shake hands with everyone else, there are 21 handshakes. (below copied from my answer of a similar question) This is an arithmetic progression and can be solved with the equation Sn=(1+(n-1))(n-1)/2 where Sn is the total sum of handshakes for n people. NB: I have used n-1 instead of n in the equation for the sum of an arithmetic progression, because you're not really going to shake hands with yourself, so you don't include the nth term, in this case 7. Alternatively, you can solve this geometrically by drawing a heptagon, drawing lines between all the vertices, and then adding all the lines up.
If There are 5 people at a party Each person must shake hands once with every other person at the party How many handshakes does it take to do this?
10 times
How many hand shakes if 12 people shake hands with every other person in room?
72
How many hand shakes would take place if 20 people shake hands once?
First person shakes hands 19 times, second person 18 etc, a total of 190.
What is the angle of the hands of a clock at 7.10?
The two hands make an angle of 155 degrees (and 205 degrees).
How many handshakes are there if 100 people all shake hands?
4950 handshakes, that is the definite answer
How many handshakes are there if 4 people shake hands?
12
How many handshakes are there if 200 people all shake hands?
4950
Four people in a room. Each shakes hands with each of the others once. How many handshakes are there?
9 handshakes correct answer is 10
How many handshakes would there be if 100 people shook hands?
200? D:
There are five people in a room Each person shakes the hand of every other person exactly once How many handshakes are exchanged?
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.
There are 10 people they all shake hands how many hand shakes are there?
45 handshakes
How many handshakes can occur between 5 people if everyone shakes hands?
10
How many people would you need to guarantee that there were at least 1000 handshakes?
You could never guarantee 1000 handshakes because the people may choose not to shake hands! If each person did shake hands with everyone else, then 46 people would suffice.
Seven people come to a party and shakes hands with each other if each person shakes the hand of every other person how many hand shakes occur?
If there are seven people, then the number of handshakes is 7*6/2 = 21
If each of seven persons in a group shakes hands with each of the other six persons then a total of forty-two handshakes occurs?
The answer is 21 handshakes because the first person shakes hands with the other 6 people. The second person shakes hands with 5 people because they already shook hands with the first person. The third person shakes hands with 4 people because they already shook hands with the first and second person. The fourth person shakes hands with 3 people because they already shook hands with the first, second, and third. The fifth person shakes hands with 2 people because they already shook hands with the first, second, third, and fourth person. The sixth person shakes hands with the seventh person because the rest have already shaken hands with them. The seventh person doesn't have anyone else to shake hands with. Therefore the answer is 21 handshakes.
there are 3 people at a party if each person mis shake hands with every person at the party exactly once how many handshakes will there be?
So, there will be 3 handshakes among the 3 people at the party.
