At a resturant, you can choose from four omelet filings: cheese,peppers,tomatoes,and mushrooms. How many different omelets you can choose from with three different fillings.
P.S., orde does not matter. I need the formula, not the answer. thank you.
2007-10-27 15:20:41 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
You want combinations, not permutations, since using ingredients A,B, and C gives the same omlet as one of the permutations such as A,C,B.
You should learn why the following formula works. It is based on the permutations of n things which is n!. But then you have to divide out by permutations that are repeats of the same combination. The formula you want is
4C3 = 4!/[3! x (4-3)!
2007-10-27 15:34:07 · answer #1 · answered by baja_tom 4 · 0⤊ 0⤋
This is a permutation problem, so you can use the permutation formula. Let number of fillings be F and 3= number of fillings in each combo:
Combos= (F!)/(3!)(F-3)!,
Since F=4, Combos = (4*3*3*1)/ [ (3*2*1)(1)]=4
2007-10-27 22:27:10 · answer #2 · answered by cattbarf 7 · 0⤊ 1⤋
You use the combination formula from statistics in which order does not matter.
The formula would be n!/[(n-k)!k!] where n = 4 and k = 3.
Below is a website that may explain the idea better than me:
http://mathforum.org/dr.math/faq/faq.comb.perm.html
Good luck.
2007-10-27 22:34:17 · answer #3 · answered by Anonymous · 0⤊ 0⤋
combination formula:
nCr = n! / [ (n - r)! * r! ]
n = number of trial (4)
r = rate (3)
so 4C3 = 4! / [(4 - 3)! * 3!] = 4 ways <== answer
2007-10-27 22:31:37 · answer #4 · answered by Anonymous · 0⤊ 0⤋
You can use the combination formula found here
http://en.wikipedia.org/wiki/Combination
2007-10-27 22:26:13 · answer #5 · answered by Frostie K 1 · 0⤊ 0⤋
basicly its 4 exponant 4 =256 i don't really know why, its what my math teacher said
2007-10-27 22:26:31 · answer #6 · answered by Shadowstrike 3 · 0⤊ 2⤋
n=number of choices
(n)(n-1)(n-2)(n-3)...
2007-10-27 22:23:35 · answer #7 · answered by dunnohow 4 · 0⤊ 2⤋