A rectangular Box 60 m long and 40 m wide has two concrete crossroads running in the middle of the box and rest of the box has been used as a lawn. The area of the lawn is 2109 sq. m. what is the width of the road?  Choose the correct choice from the following options:  A) 3 m  B) 4 m  C) 5 m  D) 6 m  E) 2 m

Rationale: total area of cross roads = 60 x + 40 x − x 2 but total area of the cross roads = 291 m 2 hence , 60 x + 40 x − x 2 = 291 ⇒ 100 x − x 2 = 291 ⇒ x 2 − 100 x + 291 = 0 ⇒ ( x − 97 ) ( x − 3 ) = 0 ⇒ x = 3 answer : a
Answer: A