Solution:
Given that, the dimension of the rectangle is 50m by 40m. The width of the longer and the shorter roads are 2 m and 2.5-m-respectively.The area of the roads = (Length × Width of longer road) + (Breadth × Width of shorter road) − (Total area of rectangular field).
Calculating the remaining portion of the field = Total area of rectangle − the area of the roads.
The area of the remaining portion of the field is 1805 and the area of the roads is 195 .
Therefore, the correct answer is option 1.