貨運百科

此文章來自奇摩知識+如有不便請留言告知

標題:

f.3 maths ~~~~~~~~

發問:

In a dice game,the player first pays $10for the game and then tosses two dice.If the sum of the numbers shown is greater than or equal to 9,the player will be reward with $20,otherwise the player will be rewarded with $n.(a)if n=2,what is the expected reward for the player?Is the game fair to the player?Why?(b)... 顯示更多 In a dice game,the player first pays $10for the game and then tosses two dice.If the sum of the numbers shown is greater than or equal to 9,the player will be reward with $20,otherwise the player will be rewarded with $n. (a)if n=2,what is the expected reward for the player?Is the game fair to the player?Why? (b) find,correct to the nearest integer,the least value of n such tht the game is more favourable to the player. 更新: y99shto : sorry!your answer is wrong! 更新 2: sorry,you still wrong!=.=

最佳解答:

In a dice game,the player first pays $10for the game and then tosses two dice.If the sum of the numbers shown is greater than or equal to 9,the player will be reward with $20,otherwise the player will be rewarded with $n. (a)if n=2,what is the expected reward for the player?Is the game fair to the player?Why? Possible outcome of two dice greater than or equal to 9: 3 and 6 4 and 5 4 and 6 5 and 5 5 and 6 6 and 6 totally 6 possibilities greater than or equal to 9. Total possible outcomes = 6×6 = 36 So expected reward = (6/36)($10) + [(36-6)/36]($n) = $10(1/6) + $n(5/6) = $(10 + 5n)/6 .......... (*) When n = 2, the expected reward = $(10 + 5*2)/6 ........... substitute n=2 into (*) = $20/6 = $3.3333 (to 4 decimal places) As $3.3333 $10. $(10 + 5n)/6 > $10 ........ from (*) 10 + 5n > 60 5n > 50 n > 5 So at least 6 (to the nearest integer) so that the game is more favourable to the player. 2006-12-08 23:35:54 補充： Sorry.. i misread $20 and $10. So expected reward= (6/36)($20) + [(36-6)/36]($n)= $20(1/6) + $n(5/6)= $(20 + 5n)/6 .......... (*)When n = 2,the expected reward= $(20 + 5*2)/6 ........... substitute n=2 into (*)= $30/6= $5 As $5 $10.$(20 + 5n)/6 > $10 ........ from (*)20 + 5n > 605n > 40n > 8So at least 9 (to the nearest integer) so that the game is more favourable to the player.

其他解答:6A560DB68EC65D60