I'm only 10 so don't lagh at me when I ask this math question.
Quetion#1:Mario has 6 T-shirts. He needs to choose 3 T-shirts to take on a trip. How many different combinations of 3 T-shirts can he choose?
Question#2: What is the sum of the angles of an octagon?
2007-01-11 12:43:13 · 5 answers · asked by Jeany 2 in Science & Mathematics ➔ Mathematics
Imagine that t-shirts are A,B,C,D,E,F.
I think that 20 combination are possible if you don't consider the order, ABC and CAB are only 1 combination.
ABC, ABD, ABE, ABF, ACD, ACE, ACF, ADE, ADF, AEF, BCD, BCE, BCF, BDE, BDF, BEF, CDE, CDF, CEF, DEF.
the formula is: 6! / (3!*(6-3)!)=20
if the boy needed 4 t-shirts: 6! / (4!*(6-4)!)=15
where ! is factorial.....
2007-01-11 13:49:29 · answer #1 · answered by sparviero 6 · 0⤊ 0⤋
Question 1 :
Let 1 be the first t-shirt, 2 be the second and so on.List all the combinations, start with the ones that have t-shirt 1
123
124
125
126
then 1 and 3
134 (132 was above already)
135
136
145
146
156 10 already! Then the remaining with t-shirt 2
234
235
236
245
246
256 6 more!
345
346
356 3 more!
456 1 more!
20 in total!
2007-01-11 21:04:18 · answer #2 · answered by belalondres 1 · 0⤊ 0⤋
1 make a drawing and write all the possibilites out in a list the answer is 20
shirts 1 2 3 4 5 6
123 124 125 126 134 135 136 145 146 156 234 235 236 245 246 256 345 346 356 456
2 1080
2007-01-11 20:57:14 · answer #3 · answered by Anonymous · 0⤊ 0⤋
I can help you with question #2
The answer is 1080 degrees.
Check out this site for information about how to do this problem:
http://regentsprep.org/Regents/math/poly/LPoly1.htm
As for the first question...you got me. Sorry I couldn't help you. I know that there are 720 combinations for the 6 shirts, but not sure how grouping three together changes this. Sorry :(
2007-01-11 21:00:22 · answer #4 · answered by SteveO 2 · 0⤊ 0⤋
6x5x4=120
180(n-2)
180(8-2)
180(6)
1080
2007-01-11 20:57:14 · answer #5 · answered by 7 · 0⤊ 0⤋