Combination Of Springs

A mass of kg is put on a flat pan attached to a vertical spring fixed on the ground as shown in the figure. The mass of the spring and the pan is negligible. When pressed slightly and released, the mass executes a simple harmonic motion. The spring constant is N/m. What should be the minimum amplitude of the motion, so that the mass gets detached from the pan? 
(Take m/s²) 

1.	cm
2.	cm
3.	any value less than cm
4.	cm

A spring of force constant is cut into lengths of ratio . They are connected in series and the new force constant is . Then they are connected in parallel and the force constant is . Then is:

1.		2.
3.		4.