百分數1題(easy!)
2006-10-19 5:11 am
The length of a rectangle is increased by 20% and the area has an increase of 2%. Find the percentage change in the breadth of the rectangle.
回答 (2)
2006-10-19 5:32 pm
✔ 最佳答案
let x be the length of a rectangle and y be the breadth of the rectangle and z be % of y[(1 + 20%)x * zy - xy] / xy = 2%
(1.2zxy - xy) / xy = 2%
1.2zxy - xy = 0.02xy
1.2zxy = 1.02xy
1.2z = 1.02
z = 0.85
Therefore the breadth of the rectangle decreases 15%.
2006-10-19 5:24 am
The breadth has a decrease of 15%.
收錄日期: 2021-04-12 22:41:02
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061018000051KK04311