Find the scale factor when given Area 1 and Area 2, inches to feet

Question

A map of a square auditorium shows the actual room has an area of 3600 feet? The scale drawing has an

area of 9 feet? What is the scale of the drawing?

А )1 in = 400 feet

B) 1 in = 20 feet

C) 3 in = 400 feet

D) 3 in = 20 feet

To find the scale factor when given Area 1 and Area 2, I divided the second area by the first area.

9 / 3600 = 1/400 square root , 1/20

But the answers are in inches to feet. I'm confused. What do I need to do next? Please help. Thanks.

Answer 1

sqr9/sqr3600= 3/60= 1/20

12in/20 ft= 1 in to 20/12- 5/3

1 inch to 5/3 or 1 2/3 feet

none of the answers are correct

oddly "best" or closest answer is d) which is the same as 1 inch to 20/3 or 6 2/3 feet

but they probably want b)