OG PS-Q132

[yinying]

132. A company that ships boxes to a total of 12 distribution centers uses color coding to identify each center. if either a single color or a pair of two different colors is chosen to represent each
center and if each center is uniquely represented by that choice of one or teo colors, what is the minimum number of colors needed for the coding?
(Assume that the order of the colors in a pair does not matter.)

(A) 4
(B) 5
(C) 6
(D) 12
(E) 24

答案:B

不太董題目要什麼??且怎麼求出來答案

[redeyes[origen]]

題目應該是說公司最少可以用幾種顏色區分不同的distribution center. 因為每個center可以用一個或兩個顏色代表, 所以我是這樣算:
設可以用X種顏色來區分各個center,
X+Cx|2>=12
若x=4, X+Cx|2=4+6=10<12
若x=5, X+Cx|2=5+10=15>12
故至少等於5