The length of a rectangle is twice its breadth. If its lengthis decreased by 5cm & breadth is increased by 5cm, the area of the rectangle is increased by 75sq.cm. What is the length of the rectangle?  Choose the correct choice from the following options:
A) 25 cm	B) 30 cm	C) 40 cm	D) 45 cm	E) 60 cm
Let breadth =x cm   Then, length =2x cm   Area =x×2x=2x2 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)=2x2+75⇒2x2+10x−5x−25=2x2+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   40 cm
<result>C</result>
The length of a rectangle is twice its breadth. If its lengthis decreased by 5cm & breadth is increased by 5cm, the area of the rectangle is increased by 75sq.cm. What is the length of the rectangle?