The length of a rectangle is twice its breadth. If its length is decreased by 10 cm and breadth is increased by 10 cm, the area of the rectangle is increased by 75 sq.cm. What is the length of the rectangle? Answers:
A) 25 cm B) 35 cm C) 30 cm D) 45 cm E) 55 cm
Let breadth =x cm   Then, length =2x cm   Area =x×2x=2x^2 sq.cm.   New length =(2x−10) cm   New breadth =(x+10) cm   New area =(2x−10)(x+10) sq.cm.   Given that, new area = initial area +75 sq.cm.   ⇒(2x−10)(x+10)=2x^2+75   ⇒2x^2+20x−10x−100=2x^2+75   ⇒10x−100=75   ⇒10x=75+100= 
<gadget id="calculator">75+100</gadget>
<output>175</output>
175   ⇒x=175/10= 
<gadget id="calculator">175/10</gadget>
<output>35/2 = around 17.5</output>
17.5 cm   Length=2x=2×17.5=35 cm   ANSWER:35 cm
<result>B</result>
The length of a rectangle is twice its breadth. If its length is decreased by 10 cm and breadth is increased by 10 cm, the area of the rectangle is increased by 75 sq.cm. What is the length of the rectangle?