How many different four letter alarm codes cam be formed for a house alarm if you can use any uppercase letter in the alaphabet without being repeated

The area of a square floor on a scale drawing is 64 square centimeters, and the scale drawing is 1 centimeter: 3 ft. what is the area of the actual floor? what is the ratio of the area in the drawing to the actual area? the area of the actual floor is square feet. the ratio of the area in the drawing to the actual area is 1 square centimeter: square feet.