The correct option is C $100,000
Amount of water the tank can hold = volume of the tank
1 L=1000 cu cm
⇒125 L=125×1000=125000 cu cm
Volume of the tank =s3=125000 cm3, where s is the side length of the tank
⇒s=3√125000=50 cm
The outer walls of the tank need to be painted, i.e., the lateral surface area of the tank needs to be painted.
Lateral surface area of the tank =4×s2=4×502=4×2500
=10000 sq cm
Painting cost =$10 per sq cm
Cost of painting the walls of the tank =10×10000=$100,000