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. What is the length of the rectangle
Choose the correct choice:
A) 18 cm  B) 16 cm  C) 40 cm  D) 20cm  E) 28 cm
Explanation:   Let breadth =x cm   Then, length =2x cm   Area =x×2x=2x^2 sq.cm.   New length =(2x−5) cm   New breadth =(x+5) cm   New area =(2x−5)(x+5) sq.cm.   Given that, new area = initial area +75 sq.cm.   ⇒(2x−5)(x+5)=2x^2+75   ⇒2x^2+10x−5x−25=2x^2+75   ⇒5x−25=75   ⇒5x=75+25= 
<gadget id="calculator">75+25</gadget>
<output>100</output>
100   ⇒x=1005=20 cm   Length =2x=2×20=40 cm   Answer: Option 40 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. What is the length of the rectangle