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?	Choose the correct choice from the following answers.
A) 25 cm
B) 35 cm
C) 30 cm
D) 45 cm
E) 55 cm

Rationale: "let breadth = x cm then , length = 2 x cm area = x × 2 x = 2 x ^ 2 sq . cm . new length = ( 2 x − 10 ) cm new breadth = ( x + 10 ) cm new area = ( 2 x − 10 ) ( x + 10 ) sq . cm . given that , new area = initial area + 75 sq . cm . ⇒ ( 2 x − 10 ) ( x + 10 ) = 2 x ^ 2 + 75 ⇒ 2 x ^ 2 + 20 x − 10 x − 100 = 2 x ^ 2 + 75 ⇒ 10 x − 100 = 75 ⇒ 10 x = 75 + 100 = 175 ⇒ x = 175 / 10 = 17.5 cm length = 2 x = 2 × 17.5 = 35 cm answer : b"
Answer: B