我有兩條數學題唔識做,各位好心人唔該列條式(連步驟)+答案比我.最好就解釋埋比我聽點解咁樣計.
1.The area of a school hall has increased by 23% after re-construction.What percentage of the previous area is the new area?
2.Florence has a piece of sticker which is trapezoidal.The shorter base of the sticker is 1.5cm,the longer base is 3cm and the height is 4cm.What is the area of the sticker?
thx!!!!=]
急!!有關數學既問題(15點!!)
2010-08-11 7:23 pm
回答 (2)
2010-08-11 7:41 pm
✔ 最佳答案
1. Let x be the previous areax (1 + 23%) = 1.23x ..............23% = 0.23
New area = 1.23x
percentage of the previous area is the new area:
(x / 1.23x) (100%) = (1 / 1.23) (100%) = 81.3%
2.
Area of trapezoid = (1/2) (shorter base + longer base) (height)
= (1/2) (1.5 + 3) (4)
= 9 cm^2
2010-08-11 9:34 pm
收錄日期: 2021-04-19 22:58:44
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100811000051KK00443