LOL, been a long time since i played with 7th grade math- Scale?

The question is:

3. A map of a rectangular park has a length of 4 inches and a width of 6 inches. It uses a scale of 1inch for every 30 miles.

a. what is the actual area of the park? Show how you know.

1in =30 miles

6x30= 180            4x30=120  180x120= 21,600 square miles

Right?

b. The map needs to be reproduced at a different scale so that it has an are of 6 square inches and can fit in a brochure. At what scale should the map be reproduced so that it fits on the brochure? Show your reasoning.

The diagram is 6x4, so it has an area of 24 square inches. I would have to divide by 4 to get 6 square inches. So I would multiply 6 by 1/4 and 4 by 1/4 to get the dimensions that they would need right?

Or since I know that 2x3=6 can I figure out the scale with that?