- Ramp is a kind of surface
- As roughness of a surface increases , friction will increase
- Hence, as roughness of the ramp increases, friction will increase

- As roughness of the ramp increases, friction will increase
- Putting a rough paper on the ramp will increase the roughness of the ramp
- Therefore, putting a rough paper on the ramp will increase the friciton of the ramp

Therefore, putting a rough paper on the ramp will increase the friciton of the ramp
[Question]Which material should be used on a bicycle ramp to increase friction?
[Context]- Ramp is a kind of surface 
- Putting a rough paper on the ramp will increase the roughness of the ramp 
- As roughness of a surface increases , friction will increase