Two towns that are 31.5 km apart are 3 cm apart on a map. What is the scale of the map?
A)1 cm=29.5 km
B)1 cm=9.5 km
C)2 cm=21 km
D)2 cm=18 km
This was one question that I was confused about...Please help...

Question

anonymous · Answer

3 cm is 31.5 km apart and 1 cm is x km apart...proportion time...
3/31.5 = 1/x (cross multiply)
(3)(x) = (31.5)(1)
3x = 31.5 (divide by 3 on both sides to get x by itself)
3x/3 = 31.5/3
x = 10.5 (1 cm = 10.5 km apart)
which is not an answer....but , 2 cm x 10.5 km = 21.

ANSWER : 2 cm = 21 km

anonymous · Answer

Thank you.

anonymous · Answer

Any other answers?

anonymous · Answer

I've already looked everywhere, and my mom can't help me and neither can my familila. So, this is the only answer. Duhhh...

anonymous · Answer

scale=Map distance/Ground distance
        =3cm:3150000=1:1050000=1cm:10.5km
so from the choices it is the same as with 2cm:21km Ans Is C

anonymous · Answer

Thanx again..