Distance covered by Bhavana in one round = Perimeter of the square field

= 4 × side of square field = 4 × 80 m = 320 m

Distance covered in 10 rounds = (320 × 10)m = 3200 m

Distance covered by Sushmita in one round

= Perimeter of the rectangular field

= 2 × (length + breadth)

= 2 × (150 + 60)m = 2 × 210 = 420 m

Distance covered in 8 rounds = 420 × 8 = 3360 m

Hence, Sushmita has covered 160 m more than the distance coverd by Bhavna.