Calculate the equilibrium constant kc she obtained for this

Question

A student ran the following reaction in the laboratory at 227 K:

2NOBr(g)<-----> 2NO(g) + Br₂(g)  

When she introduced 0.140 moles of NOBr(g) into a 1.00 liter container, she found the equilibrium concentration of Br₂(g) to be 1.51×10^-2 M.  

Calculate the equilibrium constant, K_c, she obtained for this reaction.  

K_c = ________