area

vishal chugh wrote:Q. Rectangular Floors X and Y have equal area. If floor X is 12 feet by 18 feet and Floor Y is 9 feet wide, What is the length of Floor Y, in feet?


A. 13.5 B. 18 C. 18.75 D. 21 E. 24

Solution:
It can be easily observed that one dimension of floor X = 18 feet is twice the given dimension of floor Y = 9 feet.
Hence, since the area has to remain the same for both floors, the other dimension of floor Y should be twice the other dimension of floor X = 12, which makes it 2*12 = 24.

vishal chugh wrote:Q. Rectangular Floors X and Y have equal area. If floor X is 12 feet by 18 feet and Floor Y is 9 feet wide, What is the length of Floor Y, in feet?


A. 13.5 B. 18 C. 18.75 D. 21 E. 24

The area of a rectangle is: Area = length x width

We are given that floor X is 12 feet by 18 feet and that floor Y is 9 feet wide. So we can say:

length of X = 12

width of X = 18

width of Y = 9

length of Y = n

We also can say:

Area of Floor X = Area of Floor Y

(length of X)(width of X) = (length of Y)(width of Y)

(12)(18) = 9n

(12)(2) = n

24 = n

The answer is E