题目

Jin Seng drove from town A at 09 15 hours and stopped along the way for lunch at 12 30 hours.He spent 45 minutes for lunch and drove for another 60 minutes to arrive at town B.The distance between town A and B is 900km.
       (a) Find his average speed in km/h
       (b) On his return journey,he drove on the same route continuously without stopping at 60km/h .How long will he take to arrive at town A
2.On a map,a length of 2cm represents an actual distance of 400 m.Calculate the
    (a) the actual distance,in kilometers,represented by 18cm
   (b) the area on the map,in square centimeters,given that the actual area is (2km square)

提问时间：2020-10-13

答案

减掉他吃饭的45分钟他一共开了4小时15分钟,也就是4.25个小时.速度=路程除以时间,900除以4.25约等于211.76.所以答案是211.76km/h
时间=路程除以速度,900除以60=15.答案是15小时
地图上每2厘米就等于现实中400米,也就是说每1厘米等于200米.18乘200 是3600米,除以一千是3.6千米.答案是3.6km
现实中2000平方米,边长等于20倍根号5米,除以两百约等于0.22,也就是说再地图上是0.22厘米.0.22的平方是0.05.答案是0.05平方厘米
手机打字不容易.