Length of the rectangular playground = 120 m Breadth of the rectangular playground = 90 m
∴ Perimeter of the rectangular ground = 2(l + b)
= 2(120 + 90) m = 420 m
Thus, in one complete round, boys covers a distance of = 420 m
∴ Distance covered in 15 complete rounds = 420 m x 15 = 6300 m