How many photons are absorbed in this question?

Use E=mc*delta-theta* to find the energy absorbed by the water. I forget the value of 'c'(the specific heat capacity) for water. Anyways, next use E=hc/lamba to calculate how much energy each photon can give to the water. Divide the energy absorbed by the water by the energy of each photon to get your answer. Just put in the appropriate values in the expression [mc(*delta-theta*)(*lambda*)/hc].