Electrical Engineering: Control system MCQ

Consider the unity feedback control system shown. The value of K that results in a phase margin of the system to be 30º is _______. (Give the answer up to two decimal places). 

A closed loop system has the characteristic equation given by s³ + Ks² + (K+2)s + 3 = 0. For this system to be stable, which one of the following conditions should be satisfied?