math
posted by keisha on .
A map of Australia has a scale of 1 cm to 120 km. If the distance between Melbourne and Canberra is 463 km, how far apart are they on the map, to the nearest tenth of a centimeter?
I got 3.9 cm. I made a proportion 1/120=x/463 and that's how I got 3.9. Is this right?

Yes.

120 km = 463 km
.... 
1cm(map) map distance (cm)
Crossmultiply to get algebra equation.
120x =463
x = 463/120 = 3.858333333 (round off to 3.9 since 3.858 is closer to 3 9/10 than
3 8/10  always round up from 5 or greater 3.8(58)
x = 3.9 cm
so ya I think that should be the right answer ;) =) I had trouble with that one too. I'm from Insight so I know. I hope you get it right ;) =)