A mixture of CO2, CO and O2 is in equilibrium at a specified temperature and pressure. Now

Question:

A mixture of CO2, CO and O2 is in equilibrium at a specified temperature and pressure. Now the pressure is tripled,
(a) Will the equilibrium constant K change?
(b) Will the number of moles of CO2, CO and O2 change? How? (Enter 1 if increases, 2 if decreases, and 3 if no change)