maths (rate)必須有過程 急一天(20分)

1.it is a given that the scale of a map is 1cm to 200m .if the acual distance beteen

a playground and a library is 700m ,
find the distance between them on the map.

Sol

200m：1cm

= 20000cm：1cm

=20000：1

700m *1/20000

= 0.035m

= 0.035m * 100cm /m

= 3.5cm



2.it is a given that the scale of a map is1：10000.For two building which are 800m

apart,find the distance between them on the map.

Sol

800m

= 800m *1/10000

= 0.08m

= 0.08m * 100cm /m

= 8cm



3.On a map ,the distance between city A and city B is 8cm .if the scale of the map

is 1：1000000,find
the actual distance between the two cities.

Sol

8cm *1000000

= 8000000cm *(1/100)m/cm

= 80000m

= 80000m *(1/1000)km/m

= 80km

1. The distance betweena playground and a library on the map:
( 700/200) cm
= 3.5 cm


2010-04-22 19:05:45 補充：
2. The distance between two building on the map:
(800/10000) m
= 0.08 m
= 8 cm

2010-04-22 19:11:08 補充：
3. The actual distance between city A and city B:
(8*1000000) cm
= 8000000 cm
= 80 km