How many kilograms of NaCl and how many kilograms of MgSO4 are contained in 45,000 kg of this solution.?

Salinity is a term much used in water conservation and is defined as the total m (in grams) of all salts dissolved in a 1-kg water sample. You are told to prepare a solution of 85 parts per thousand salinity (85 g. of salts per kg of solution) to test the effect on food crops of irrigating farmland with high salinity river water. The solution contains twice as many moles of dissolved NaCl as dissolved MgSO4, and these are the only solutes.