Puzzle of the week
There are 10 friends at a party. Everyone shakes hands with each other once.
How many total handshakes will be there?
What students worked out13
Student 11
55
Student 17
The answer is 45 because the first shakes hands with 9 not 10.Then it will keep reducing all the way to 1.
Student 4
45 ways because the first person shakes hands with the other nine people. The 2nd person shakes hands with 8 people as he already shook hands with the first person. So what we do is:
9+8+7+6+5+4+3+2+1=45
We don’t add 10 as the 10th person already shook hands with everyone else.Student 2
45
Student 18
I noticed that you can use triangular numbers in this case so the 9th triangular no.= 45
triangular nos. are addition of numbers so ,
1st triangular no.= 0 + 1 = 1
2nd= 1+2 =3
3rd = 3+3 = 6
so then
9th = 36+9 = 45
or we can do it with the help of the attached figure , where the dots represent the people and the line represents handshakesStudent 15
so first I multiplied 9 into 10 as 1 will shake hands with 9 people but as it continues the number before already has shaked there hand so its actually the half of 90 which is 45
Student 15
so 1 number has 1 less handshake then their predecessor
Student 14
45 or 55 handshakes
Student 9
There are 45 handshakes all together.
Student 1
45 ways
Student 1
Handshakes because
for example A shakes hands with B the b doesn`t shake hands with a again
Student 3
9+8+7+6+5+4+3+2+1+0= 45
Student 3
9+8+7+6+5+4+3+2+1+0= 45
this is what i found