the reactance X of a capacitance C and an inductance L in series is:

x=wl-1/wc

x=1500

l=0.5

c=0.2x10^-6

0.5w-1/w*0.2*10^-6=1500

0.5w-5*10^6/w=1500.

0.5w^2-5*10^6=1500w.

0.5w^2-1500w-5*10^6=0.

By solving aboive qyadratic

w=5000,-2000.

take only positive value as w can never be negative.

w=5000.