12)
A=LW in this case:
A=10*4
A=40 ft^2 (40 square feet)
13)
Since when rounding to the nearest 100, it rounds to 400, the number must be greater than or equal to 350...
n≥350
When rounded to nearest 10, it rounds to 350, so n<355....
350≤n<355
Only C., 352 can satisfy the inequality.
