Answer:
100 m
Step-by-step explanation:
Lalith purchased a total of 8 × 20m = 160 m of wire for ₹800, so paid ...
(₹800)/(160 m) = ₹5/m
Shekhar paid ₹800 -300 = ₹500 less, so must have purchased ...
(₹500)/(₹5/m) = 100 m
less wire.
The difference between the field perimeters is 100 m.