[問題]GWD24-4

[magic]

4
A shipment of 8 television sets contains 2 black-and-white sets and 6color sets. If 2 television sets are to be chosen at random from this shipment, what is the probability that at least 1 of the 2 sets chosen will be a black-and-white set?
A. 1/7
B. B. ¼
C. C. 5/14
D. D. 11/28
E. E. 13/26
答案是E
可是我怎麼算都是15/28ㄟ
是我算錯了還是答案有問題阿??

[kwtluck]

因為題目說至少一台是黑白,妳算15/28是兩台都是彩色
還要用1-(15/28)=13/28[1-兩台都是彩色=至少一台黑白]

[magic]

謝謝唷
頭腦錯亂了^^"

[melanie0420]

挖勒
那答案選項也是寫錯啊
明明13/28 是誰搞成13/26啊??