Re: [計量] 請問幾題數學
※ 引述《ipathigo (機哩呱啦)》之銘言：
: 1.How many different three-digit even numbers can be formed from the set of
: integers from 1 to 9 inclusive if no digit may appear twice?
: Ans: 224
: 符合even numbers 的不是只有2 4 6 8 四個數字，要排在三位，我怎麼算都沒有破百
: 種的可能@@
three-digit even numbers是指三位數的偶數 不是說三個都要偶數
所以是把個位數選2468 十位跟百位就認選
8(百位)x7(十位)x4(個位2468)=224
: 2.In how many different arrangements can six guests and one host be seated
: at a round table?
: Ans: 720
就直接6!=720
: 這種題目真的是我的死穴，不知道要怎麼解答
: 3.Before the start of a horse race, and based on the past performance of the
: horse entered, the spectators are told that the chance are 4 to 1 that Aegis
: will win.What is the probability that Aegis will lose?
: Ans:1/5
: 不是很單純，1/4的贏，就代表3/4的輸，我知道我錯了，但是不知道為什麼!!
4 to 1是4(W):1(L)
所以輸的機會是1/5
: 4.If two cards are drawn at random without replacement from a standard deck
: of 52 cards that contain four different suits of 13 cards each, what is
: the probability that both cards will be of a given suit?
: Ans:1/17
13/52(第一張的花色)x 12/51(第二張的花色)=1/17
: 真的不行，都忘光了@@
: 麻煩各位幫忙一下了
: 謝謝大家
其實Q是在考你英文好不好............XD
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