Hi can I please have some help with this question. I tried using Kc= (c)^2 x (D)/ (B)^2 X (A) but I realised that I am not given their concentration . How would I go about this question please ?

Consider the following reversible reaction at temperature T. A + 2B β 2C + D

At equilibrium, there are 0.5 moles of A, 0.2 moles of B, 0.5 moles of C and 0.8 moles of D, all in a vessel of volume V.

What is the value of the equilibrium constant, Kc, at this temperature?