急~中一數學一問(詳細回答)

2007-08-28 5:40 pm
The monthly salary of an engineer is $9500. This is increased by 8% after a year. By how much is his monthly salary increased in the second year?
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The price of a TV set decrease from $8800 to $7744. What is the percentage decrease?
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A machine is bought for $450000 and a profit of $9000 is made. Find the percentage profit.
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The profit on selling an article is 44% of its cost price. If the profit is $1056, find the selling price of the article.
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1.5cm : 4.5km

回答 (1)

2007-08-28 6:40 pm
✔ 最佳答案
1) 因為佢只係問第二年佢既薪水上升左幾多錢,所以我地張9500成番8%就搵到佢加大幾多錢(=上升左幾多錢)
9500x8%
=9500x0.08
=760
2) (新值 - 原值)/原值 x100% 搵到百分數既增減
(7744-8800)/8800 x 100%
= -1056/8800x100%
= -12% (計數機個答案可能係點數-0.12 ,姐係= -12%)
3)衣條又係用番第二條嗰條式
9000就係machine既profit 姐係新值減左原值既既數目,所以就可以即刻用黎計
450000-9000=441000 (因為9000係profit,所以張新值-佢賺左幾多(9000)就可以搵到原值
9000/441000x100%
= 2% (大約值)
4) 設cost price of the article be y
y*成44% = 1056 (因為題目話profit 係 cost既44%)
    0.44y = 1056
y = 2400
cost price 係2400
selling price = 2400+1056 ( 成本再加佢既profit 就會= 佢既selling price)
= 3456
5) 1.5cm : 4.5km
1.5cm : 4.5(100)(1000) 張佢化番做cm (做衣d數既時候,單位要一樣先可以計到) 1.5cm : 4500000cm 兩邊除1.5 就會變做1:幾
1 : 3000000
( 衣條唔係好肯定你想問乜,我估你係想問點轉番做一比幾) 

希望幫到你啦!!
參考: me


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