1) If the value of x after increased by 40% is equal to the sum of 2500 and the value of x after decreased by 10%, find the value of x after decteased by 20%.
2) During the big sale of a department store, all goods are sold at a discount of 10%. If the marked price of a television set is $ 11000 and the profit per cent is 10%, find the cost of the television set.
math 急用...
2009-07-08 10:31 pm
回答 (2)
2009-07-08 11:09 pm
✔ 最佳答案
(1) x(1 + 40%) = 2500 + x(1 - 10%)
1.4x = 2500 + 0.9x
0.5x = 2500
x = 5000
x(1 – 20%) = 0.8x = 4000
(2)
Let the cost of the TV set by $x.
Marked price = 11,000
Discount price = 11,000 (1 – 10%) = 9,900
Profit % = (9,900 – x) / x (100%) = 10%
9900 – x = 0.1x
1.1x = 9900
x = 9,000
The original cost of a TV set is $9,000
2009-07-08 11:03 pm
1)中的 decteased=decreased??
收錄日期: 2021-04-23 23:20:04
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