Math Is Fun Forum

Monox D. I-Fly

Member

From: Indonesia

Registered: 2015-12-02

Posts: 2,000

[ASK] Minimum Dimension of a Map

The farthest distance of two places in an area is 200 km. If someone wants to make a map of that area on a 1 m × 1 m paper, the possible scale to make it is ....
a. 1 : 210
b. 1 : 2.100
c. 1 : 21.000
d. 1 : 210.000

Can you help? The 200 and 210 makes me think that the distance on map won't be an integer.

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Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away.
May his adventurous soul rest in peace at heaven.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,619

Re: [ASK] Minimum Dimension of a Map

hi Monox D. I-Fly

It looks to me that this question is about comparing the 1 metre width of the map with the 200 Km in reality.  You're right that the conversion isn't a whole number but I don't think you're meant to worry about that.

If the line is AB, 200 Km long in reality, we need to fit that line on the map.  Worst case is if its parallel with an edge. (diagonally is easier to fit)

If we made it 1 metre is equivalent to 200 Km the A and B would be right on the edge.  Most people wouldn't want that, so they've made it clearer by implying that you just need to make the width 210 Km.  Then we know the line will fit without A or B being on the very edge.

So the scale to make this happen is 1 metre : 210 Km.  Convert the second distance into metres and you've got your answer.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

Monox D. I-Fly

Member

From: Indonesia

Registered: 2015-12-02

Posts: 2,000

Re: [ASK] Minimum Dimension of a Map

1 : 210,000, then. Thanks, bob bundy!

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Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away.
May his adventurous soul rest in peace at heaven.