What is the area of a rectangle that is a perimeter of 30?

It can be 56.25 or anything less, but not more.

You can't tell the area from the perimeter, and you can't tell the perimeter from the area.

-- if each side is 7.5, the perimeter is 30, and the area is 56.25

-- if it's (5 by 10), the perimeter is still 30, and the area is 50

-- if it's (4 by 11), the perimeter is still 30, and the area is 44

-- if it's (3 by 12), the perimeter is still 30, and the area is 36

-- if it's (2 by 13), the perimeter is still 30, and the area is 26

-- if it's (1 by 14), the perimeter is still 30, and the area is 14