Methods of Increasing and Reducing Friction

Would it be easier or more difficult for you to walk on the floor of soapy water? Give reason in support of your answer.

Aabida runs her toy car on dry marble floor, wet marble floor, newspaper and towel spread on the floor. The force of friction acting on the car on different surfaces, in increasing order will be - 

Sprinkling of powder on the carrom board _____ friction.

Can friction be less or become nil by using lubricants?

Explain why sportsmen wear shoes with spikes?