1
According to Mr.Chan's will,his three sons may obtain a sum of $6000000 inheritance according to the continued ratio of their ages.The present ages of his three sons are 16,21,23 respectively.
n years later, if the amount of inheritance obtained by the eldest son is more than of thr youngest son by $437500, find the age of thr second son.
2
To complete a job alone, A needs 12 days, B needs 18 days and C needs 24 days. Now, the job is carried out by A first for several days, and then B for several days, and finally completed by C. The ratios of the working days are A:B=1:3 and B:C=1:2. Find the total number of working days for completing the job.
中二數學(ratio), please help!!!
2009-11-22 3:17 am
回答 (2)
2009-11-22 3:43 am
✔ 最佳答案
(1) n years later, their ages are 16+n, 21+n and 23+nTheir sum is 60+3n
The amount for the eldest = $6,000,000 * (23 + n) / (60 + 3n)
The amount for the youngest = $6,000,000 * (16 + n) / (60 + 3n)
The difference is $6,000,000 * (23 + n - 16 - n) / (60 + 3n) = $437,500
7/ (60 + 3n) = 437500/6000000
60 + 3n = 6000000*7/437500 = 96
3n = 36
n = 12
The age of the second son = 21 + 12 = 33
(2) Let A worked for x days.
Then B worked for 3x days.
And C worked for 2(3x) = 6x days
The portion completed by A = x/12
The portion completed by B = 3x/18 = x/6
The portion completed by C = 6x/24 = x/4
Sum of the three portion = x/12 + x/6 + x/4 = 1
x/12 + 2x/12 + 3x/12 = 1
6x/12 = 1
x = 2
The total number of working days = 2 + 3(2) + 6(2) = 20 days
2009-11-22 11:34 pm
1.據Mr.Chan氏將，他的三個兒子可以得到一筆遺產的六百點○萬美元根據比例繼續其目前的年齡ages.The他的三個兒子分別是16,21,23。
n年後，該數額繼承獲得的長子比小兒子蘇氨酸的四十三點七五萬美元，發現年齡蘇氨酸的第二個兒子。
2.
要完成工作，僅需要12天甲，乙需要18天和C需要24天。現在，這項工作開展的第一個數天，然後乙數天，終於完成了C的比例在工作日甲：乙= 1:3和B如下：C = 1:2。找到總數工作日完成工作。
我盡幫你睇,我不過是6年級,加油,唔得既你不如陣金山
n年後，該數額繼承獲得的長子比小兒子蘇氨酸的四十三點七五萬美元，發現年齡蘇氨酸的第二個兒子。
2.
要完成工作，僅需要12天甲，乙需要18天和C需要24天。現在，這項工作開展的第一個數天，然後乙數天，終於完成了C的比例在工作日甲：乙= 1:3和B如下：C = 1:2。找到總數工作日完成工作。
我盡幫你睇,我不過是6年級,加油,唔得既你不如陣金山
參考: 金山
收錄日期: 2021-04-23 23:21:31
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