A.B.C.D.E五個人接受滿分為10分的測驗。測驗的結果布的說法。
A:得了4分
B:5人中最高
C:與A和D的平均分數相等
D:與5人的平均分數相等
E:給C多2分
已知B是第一名，E是第二名，問第三.四.五名分別是誰？B的分數也是多少？
箱子內有紅波和白波。如果每次取出5個紅波、3個白波，當白波拿完了，紅波還剩8個。如果每次取出7個紅波、3個白波，當紅波拿完了，白波還剩24個。問箱子中有多少紅波？多少白波？
我想問兩條數？20分 高手請進 (急)
2007-12-04 5:18 am
回答 (3)
2007-12-04 5:32 am
✔ 最佳答案
b:101:b
2:e
3:c
4:a
5:d
2007-12-08 10:19 am
1. ALL WE KNOW ARE:
A=4,
C= (A+D)/2 = 2+D/2 ---------------(1)
D= (A+B+C+D+E)/5, -------------(2)
E= 2+C, -------------------------------(3)
B>E, ------------------------------------(4)
E>A, E>C, E>D --------------------(5)
Put (1) into (3) => E = 2+(A+D)/2 -----------(6)
Put (3) & (6) into (2) and use A=4 => D=[4+B+ 2+D/2+D+2+(A+D)/2]/5
=> D=10/3+B/3 -----------------(7)
Put (7) into (6) and use A=4 => E= 17/3+B/6 ------------------------(8)
Put (7) into (1) => C= 11/3 +B/6 ---------------------(9)
We know:
B>E => B>17/3+B/6 (Put in equation 8)
=> B > 6.8
And we also know 10 >= B, so we get the relation 10>=B>6.8 -----------------(10)
Therefore: A=4 (Original know)
10>=B>6.8 (Find)
5.33>=C>=4.8 (Use (9) and (10))
6.67>=D>=5.6 (Use (7) and (10))
7.33>=E>=6.8 (Use (8) and (10))
So, the markings:
B > E > D > C > A
We cannot find the marking result of B in accuracy. Only give out 10>=B>6.8.
2. According to all the information, we have equations:
red ball = X, white ball = Y
3n = Y,
5n = X-8, => Y/3 = (X-8)/5 ---------(1)
7m = X,
3m = Y-24 => X/7 = (Y-24)3 ---------(2)
Put (1) into (2)
=> X = 168 and Y = 96
Ans.:red ball 168pcs and white ball 96 pcs
A=4,
C= (A+D)/2 = 2+D/2 ---------------(1)
D= (A+B+C+D+E)/5, -------------(2)
E= 2+C, -------------------------------(3)
B>E, ------------------------------------(4)
E>A, E>C, E>D --------------------(5)
Put (1) into (3) => E = 2+(A+D)/2 -----------(6)
Put (3) & (6) into (2) and use A=4 => D=[4+B+ 2+D/2+D+2+(A+D)/2]/5
=> D=10/3+B/3 -----------------(7)
Put (7) into (6) and use A=4 => E= 17/3+B/6 ------------------------(8)
Put (7) into (1) => C= 11/3 +B/6 ---------------------(9)
We know:
B>E => B>17/3+B/6 (Put in equation 8)
=> B > 6.8
And we also know 10 >= B, so we get the relation 10>=B>6.8 -----------------(10)
Therefore: A=4 (Original know)
10>=B>6.8 (Find)
5.33>=C>=4.8 (Use (9) and (10))
6.67>=D>=5.6 (Use (7) and (10))
7.33>=E>=6.8 (Use (8) and (10))
So, the markings:
B > E > D > C > A
We cannot find the marking result of B in accuracy. Only give out 10>=B>6.8.
2. According to all the information, we have equations:
red ball = X, white ball = Y
3n = Y,
5n = X-8, => Y/3 = (X-8)/5 ---------(1)
7m = X,
3m = Y-24 => X/7 = (Y-24)3 ---------(2)
Put (1) into (2)
=> X = 168 and Y = 96
Ans.:red ball 168pcs and white ball 96 pcs
參考: me
2007-12-07 7:14 am
第一題:
第一名: B(6分)
第二名: E(5分)
第三名: A(4分)
第四名: C(3.8分)
第五名: D(3.6分)
B的分數: 6分
第二題:
唔識,諗到答你
第一名: B(6分)
第二名: E(5分)
第三名: A(4分)
第四名: C(3.8分)
第五名: D(3.6分)
B的分數: 6分
第二題:
唔識,諗到答你
收錄日期: 2021-04-13 17:46:18
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