The length of a rectangle is twice its breadth. If its length is decreased by 5 cm and breadth is increased by 5 cm, the area of the rectangle is increased by 75 sq. cm. Find the length of the rectangle. Choose the correct answer:
A) 10 cm
B) 15 cm
C) 20 cm
D) 18 cm
E) 24 cm
Explanation:   Let breadth = x. Then, length = 2x. Then,   (2x - 5) (x + 5) - 2x * x = 75 =&gt; 5x - 25 = 75 =&gt; x = 20.   Length of the rectangle = 20 cm.   Answer: Option 20 cm
<result>C</result>
The length of a rectangle is twice its breadth. If its length is decreased by 5 cm and breadth is increased by 5 cm, the area of the rectangle is increased by 75 sq. cm. Find the length of the rectangle.