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1.If a car travels 39 km in 31 minutes, its speed (correct to the nearest 0.1 km/h) is ??
2. The area of a rectangle is 10.8 cm2次方, 0.1 cm2次方; the width, correct to the nearest 0.1 cm, is 2.3 cm. The greatest possible value of the length, correct to 2 decimal place, is ??
3.The diameter of a circle is measured to de 8.5 cm, correct to the nearest 0.1 cm. The smallest possible circumference (Take (派) =3.14)
F.2 maths(急急急急急...)
2007-09-26 6:13 pm
回答 (2)
2007-09-26 6:25 pm
✔ 最佳答案
1. 39/ (31/60)2. when length is maximum, width is minimum. so the minimum value of width is 2.25(since 2.3 is correct to the nearest 0.1 cm)
maximum value of area is 10.84 (correct to 0.1)
therefore the greatest possible value of length is 10.84/2.25
3. similarly, the smallest circumference is 8.45 * 3.14
2007-09-26 6:18 pm
39*60/31=75.5
收錄日期: 2021-05-01 15:45:03
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070926000051KK00901