Lalit purchased two triangular plots, each of which had exactly two sides of length 100 m. Find the maximum possible difference of the perimeter of two plots, if it is known that neither of the two plots is less than 4800 sq. m in area.

Since two sides of triangles are 100 m each.

Now, the third side of triangle must be greater than '0' and less than '200'. 

The Minimum length of the third side when the area is greater than or equal to 4800 = 120 m

The maximum length of the third side when the area is greater than or equal to 4800 = 160 m

Now, Difference between perimeter of two triangle = Difference between length of third side = 160 - 120 = 40 m