Re: [計量] 請問2題數學
※ 引述《feekl (joie de vivre)》之銘言：
: 1.
: n = (28)^3
: Column A: The units of digit of n
: Column B: 4
: Ans: B > A ???
: 2.
: Seven one-dollar bills are to be distributed among three people so that
: each person receive at least $1.
: Column A: The number of ways to distribute the bills so that at least one
: person receives at least $3
: Column B: The total number of ways to distribute the bills
: 可以教我怎麼解嗎...謝謝!!
2.
column A
at least one person receives at least $3,and each person receives at least $1
so it can distribute to 511, 421, 331 and 322
the number of ways of 511 is 3
421 is 6
331 is 3
322 is 3
so all the number of ways is 15
column B
because each person receives at least $1,
you can think all of them already have $1.
And $4 are to be distributed.
the totoal number of ways is H(3取4)=C(6取4)=6*5/2=15
so the answer is the same!
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◆ From: 140.112.66.235
※ 編輯: dukeduke 來自: 140.112.66.235 (08/26 14:47)
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08/27 08:20, , 1F
08/27 08:20, 1F
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