Would it be easier or more difficult for you to walk on soapy water on the marble floor? Why?

When we walk on the floor, the friction acts opposite to the motion as shown in the figure below.

On a marble force, the surface is rough. And, we know rough surface offers more friction. But, on a soapy floor, the soap acts as a lubricant and the lubricant decreases the friction between the shoe & the floor.

So, people tend to slip on a marble floor covered with soapy water.