Problem: 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 ? 
Options: ['a ) 3 m', 'b ) 4 m', 'c ) 5 m', 'd ) 6 m', 'e ) 2 m']
a