A solid sphere rolls down two different inclined planes of the same heights but different angles of inclination. In each case, the ball will : 

Will take longer time to roll down one plane

Acceleration of the rolling sphere : 

a = gsinθ/((1+k²/R²))

Velocity of the sphere at the bottom of the inclined plane :

v=√(2gh/((1+k²/R²)))

The sphere will take a longer time to roll down one plane than the other. It will take a larger time in case if the plane with smaller inclination because the acceleration is proportional to sin θ.