Re: [計量] 請教兩題計量
※ 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
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