百分數應用題(英文)

2010-02-13 7:36 pm
A book is sold for $55 at a profit of 10%, Find the cost of the book

請清楚列式和答案

回答 (4)

2010-02-14 8:23 am
✔ 最佳答案
一本書的售價是 $55,盈利有 10%,請問成本是多少?

設成本是 x,

(x)(1+10%)= 55
(x)(110 / 100)= 55
x = 55 x 100 ÷ 110
x = 50

∴ 成本是 $50
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不信?哪我們驗証一下吧。

售價是:
(50)(1+10%)
=(50)(110 / 100)
= $55



(1+10%)的 1 是指整體
而 +10% 是因為盈利有十
如果成本是 $50 的話
售價計算出來的就是題目所說的 $55
所以成本是 $50 元這個是沒錯的

2010-02-14 00:27:24 補充:
補充一下:
而 +10% 是因為盈利有 10%(漏了 %)
參考: , 我。很久沒答過問題了,希望幫到您!
2010-02-13 8:17 pm
Let n be the cost of the book.
n (1+10%) = $55
110n/100 = $55
11n/10 = $55
11n = $550
n = $50
therefore the cost of the book is $50
2010-02-13 8:10 pm
A book is sold for $55 at a profit of 10%, Find the cost of the book

the cost of the book ,
55 x (1-10%)
= 55 x 90%
= 55 x 90 / 100
= $ 49.5
(3 點 ) the cost of the book is $ 49.5
參考: me
2010-02-13 7:49 pm
一本書售價係$55, 有10%盈利, 成本係幾多??

55 x (1-10%)
= 55 x 90%
= $49.5

Hope I can help you!!~
希望可以幫到你!!~
參考: Myself


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