A rectangular field is 16 m long and 10 m wide. There is a path of uniform width all around it, having an area of 120 m2. Find the width of the path.
Area of the outer rectangle
= (16+2x)(10+2x)
= 160+32x+20x+4x2
= 160+52x+4x2
Area of the inner rectangle
= 16m×10m
= 160m2
Area of the path
= 160+52x+4x2−160=120
or, 4x2+52x−120=0
or, x2+13x−30=0
or, (x+15)(x−2)=0
or, x=−15,2
As width can not be negative x = 2 m
i. e. width of the path = 2 m