Bunuel

In the figure shown, squares A and B are in rectangle R. The area of rectangle R is 216. The width (vertical dimension) of rectangle R is 12. The area of square A is 4 times the area of square B. The sum of the areas of squares A and B is 80. What is the value of x?
A. 1
B. 3/2
C. 2
D. 5/2
E. 3
Given:Area of rectangle = 216
Width = 12
The area of square A is 4 times the area of square B.
The sum of the areas of squares A and B is 80.
Need:What is the value of x ?
Solution:
Step 1: Lets calculate the length of the rectangle
Area of rectangle = 216
Width = 12
Area = L * W
216 = L*12
L = 216/12 = 18
Length of the Rectangle = 12
Step 2: Lets calculate area of square
The area of square A is 4 times the area of square B.
The sum of the areas of squares A and B is 80.
Lets consider area of small square is n, so area of larger square is 4n.
Based on second statement above, we have
4n+n = 80
5n=80
n=16
Area of smaller square = n = 16
Area of larger square = 4n = 64
Length of side of smaller square = 4
Length of side of larger square = 8
Step 3: Calculate the value of x
Lets take width to calculate x
Width of rectangle = Side length of A + Side length of B + 3x
Substituting 18 for width in the above equation
18 = Side length of A + Side length of B + 3x
Substitute side lengths of square A and B in the above equation
18 = 8+4+3x
18 = 12+3x
3x = 18-12
3x=6
x=2
Ans:
C