Re: [計量] 請教兩題計量

看板GRE作者 (soso)時間16年前 (2008/07/20 11:10), 編輯推噓1(100)
留言1則, 1人參與, 最新討論串2/21 (看更多)
※ 引述《usagidango (白兔糰子)》之銘言: : A gardener is going to plant 2 red rosebushes and 2 white rosebushes. If the : gardener is to select each of the bushes at random, one at a time and plant : them in a row, what is the probabilitythat the 2 rosebushes in the middle of : the row will be thw red ones? : Ans: 1/6 1/2*2/3*1/2*1=1/6 兩個白色/4顆*兩個紅色/(紅紅白)*紅色/(白紅) : Three friends are playing a game in whicheach person simultaneously displays : one of three hand signs: a clenched fist, an open palm, or two extended fingers. : How many different combinations of the signs are possible? : Ans:10 : Thanks! 因為這沒有要規定誰出什麼...所以只要算可能出現的情況 三個人都相同.............3種 兩個人相同...............3*2=6 A可以出三種 * 但BC只能出A沒出的那兩種 三個人都不一樣 1 故3+6+1=10 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 123.195.202.241

07/20 11:55, , 1F
感謝^^
07/20 11:55, 1F
文章代碼(AID): #18Wgod15 (GRE)
討論串 (同標題文章)
文章代碼(AID): #18Wgod15 (GRE)