The question is asking how many combinations of two people can be made from a group of ten people.
Using the formula C(10,2) = 10!/(2! x (10 - 2)! = 10!/(2! x 8!) = 45 handshakes.
A simple way to prove this is each person shakes the hand of 9 other people
10 x 9 = 90 but this counts every handshake from the view of both people involved.
The actual number of handshakes is therefore 90 / 2 = 45
Use the pythagorean theorem.
Answer:
b and d
Step-by-step explanation:
<h3>
Answer: 720</h3>
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Explanation:
We have 6 slots to fill A,B,C,D,E,F
There are 6 choices for choice A, then 5 choices for slot B, 4 for C, and so on until we reach one choice for slot F. Count down by 1 each time a slot is filled.
Multiply out those values to get: 6*5*4*3*2*1 = 720
For more information, check out the concept of factorials.
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Another approach is to use the nPr permutation formula which is
where in this case n = 6 and r = 6.