<PRE><B>Question 237580</B>
Let a = 4

Let b = 5

Then we can make:

4/(5 + c) = 3/7

Cross-multiply:

3(5 + c) = 4(7)

15 + 3c = 28

3c = 28 - 15

3c = 13

c = 13/3

We are looking for a:c, which is really a/c.

We know a and we just found b.

So, plug and chug.

4/(13/3) = 12/13 = 12:13

Answer is choice d.

===============================

By the way, a:b can also be written a to c, which can also be written as a/c.

They all mean the same thing.

===============================


Think about it this way:

Batman:Robin = Batman to Robin = Batman/Robin








</PRE>