1.黃先生將每月收入的15%儲蓄起來.如果他每月的支出都是$6800,求他一年的收入.
2.一個盒內有5打橙,其中只有39個橙是好的,其餘全是壞的.
a) 盒中有百分之幾的是壞的?
b) 如果再把2打好的橙放入盒中,現在盒中有百分之幾的橙是好的?
要過程and答案!! thank !!
數學!!唔識做啊!!急!! @ @
2007-12-15 3:16 am
回答 (3)
2007-12-15 6:59 pm
✔ 最佳答案
1. 假設黃先生每月的收入是 $x.黃先生每月支出的百分比 = 1 - 15% = 85%
收入 * 支出百分比 = 支出
=> x * 85% = 6800
=> 0.85x = 6800
=> x = 6800 / 0.85 = 8000
8000 * 12 = 96000
黃先生每月收入為 $8000, 一年的收入合共 $96000.
2.
a) 盒中有 5 * 12 = 60 個橙.
盒中壞橙的數目是 60 - 39 = 21
盒中壞橙的比率 = 21/60 * 100% = 35%.
b) 如果再把2打好的橙放入盒中, 盒中有 7 * 12 = 84 個橙.
盒中好橙的數目是 39 + 12 * 2 = 63
盒中好橙的比率 = 63/84 * 100% = 75%
2007-12-16 8:21 pm
1.
6800/(1-15%)x12
=8000x12
=$96000
2a.
12x5-39
------------x100%
12x5
=21
------x100%
60
=25%
2b.
12x2+39
------------x100%
12x(5+2)
=63
------x100%
84
=75%
6800/(1-15%)x12
=8000x12
=$96000
2a.
12x5-39
------------x100%
12x5
=21
------x100%
60
=25%
2b.
12x2+39
------------x100%
12x(5+2)
=63
------x100%
84
=75%
2007-12-15 3:43 am
1)$6800x(1+15%)x12
=$7820x12
=$93840
2a)39/5x12x100%
=13/20x100%
=65%
b)39+2x12/7x12x100%
=63/84x100%
=75%
=$7820x12
=$93840
2a)39/5x12x100%
=13/20x100%
=65%
b)39+2x12/7x12x100%
=63/84x100%
=75%
參考: myself
收錄日期: 2021-04-13 18:46:05
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071214000051KK02686