數學(百分數)

Let x be the cost price of the camera :
Sets the marked price of a camera so as to make a profit of 20% : marked price = $ x (1 + 20%) = 1.2x
He sells it at a discount of 10% :selling price = $ (1.2x) (1 - 10%) = 1.2x * 0.9 = 1.08x
And makes a profit of $256 : Profit = 256
Selling price - the cost = 256
1.08x - x = 256
0.08x = 256
x = 256/0.08
x = 3200
The cost price of the camera = $ 3200


2010-11-19 21:12:03 補充：
一式過 :

x(1 + 20%)(1 - 10%) - x = 256

2010-11-19 21:13:11 補充：
(1.2)(0.9)x - x = 256

1.08x - x = 256

(1.08 - 1)x = 256

0.08x = 256

x = 256/0.08

x = 3200

2010-11-20 00:46:03 補充：
001 :

You want to be selected but your answer is wrong.

Let $x be the cost price
x(20%-10%)=256
x X10%=256
x=2560
The cost price of the camerais $2560.

2010-11-19 21:34:24 補充：
hope you choose me la

2010-11-19 21:34:42 補充：
Thankyou!!!