Area of rectangular park = 60 × 40 = 2400 sq. metre Let the width of cross-road be x metre. ∴ Area of cross-roads =60x+40x−x2 =100x−x2 According to the question, 100x−x2=2400−2109 ⇒100x−x2=291 ⇒x2−100x+291=0 ⇒x2−3x−97x+291=0 ⇒x(x−3)−97(x−3)=0 ⇒(x−3)(x−97)=0 ⇒x=3 because x≠97