Hello My name is Professor Mcroberts and I am going to be teaching you about Combinations today! In class we learned about the difference between a combination and a permutation. A combination would be an equation in which order does not work to have the order specified like the permutation formula. the combination formula is expressed as follows: 300C10= 300!/10!(300-10)!
To quote Professor little's definition of the definition of a combination formula: it is the "# of distinct combinations of "r" items selected without replacements from a pool of "n" items (r<n) denoted by nCr or r!/r!(n-r)!
so say there is a concert at red rocks which has a capacity of 400. only 50 get to sit up front and do not have to sit consecutive order: what is the number of possible lineups:
400C50 = 400!/50!(400-50)! possible lineups.
There are 400 people=n
there are 50 in the front=r
so plug in those values and make the equation= 400!/50!(400-50)!= possible lineups for the concert if order DOES NOT matter.
the purpose of this experiment is to calculate the number of possible lineups or situations in which order does not matter in the experiment.
the math behind this is simple because all it is is plugging in values and solving for the number of lineups. you just plug N and R and know the equation.
the difference between a Combination and a combination is that a permutation requires order.
Thats all for today!
I liked the example you used of a concert at red rocks, because it made the lesson more interesting and easy to relate to. Good job explaining combinations, they can be difficult.
ReplyDeleteNice Job defining permutation vs. combination. I really liked your example of red rocks because thats something we all can relate too. It might be helpful to solve the problem next time but all and all good job!
ReplyDeletemac,
ReplyDeletenice job! i get to go to red rocks for the first time next may! i think there will be more than 400 people, but still a relevant example. and thanks for giving me cred in your lesson. it was nice to have you in class. good luck to you! =]
professor little