Decide which is limiting reactant-combinations of reactants

Question

At high temperatures and pressures, nitrogen will react with hydrogen to produce ammonia, as shown by the equation

___N₂(g) + ___H₂(g)   ®   ­­___NH₃(g)      

For each of the following combinations of reactants, decide which is the limiting reactant.

a. 1.25 moles of N₂ and 3.65 moles of H₂

b. 44.0 g of N₂ and 3.00 moles of H₂