Answer:
If reactants are added to a system at equilibrium, the forward reaction rate will increase. The reverse reaction rate will also increase, but not as much as the forward reaction rate. This is because the forward reaction has more reactants available to react, while the reverse reaction has the same amount of reactants and products. The net effect is that the system will shift to the product side, and the equilibrium will be re-established.
So the answer is Both reaction rates increase.