Mrs. Kaushik has a square plot with the measurement as shown in the figure.

Area of the square plot = Side² = 25² = 625 square metre

Area of the house construction part = length x breadth

= 20 x 15 = 300 sq m

Area of garden = 25² – 15 × 20

= 625 – 300

= 325 m²

Thus, total cost of developing a garden around the house at the rate of Rs 55 per m² = 325 × 55

= Rs17875