Hello candidate,

The general formula to calculate solubility of any salt is given by- Divide the mass of the compound by the mass of the solvent and then multiply by 100 g to calculate the solubility in grams per 100g.

So, as in the giv given question the mass of compound is 55 grams and the mass of solvent is 45 grams of potassium nitrate. So, the solubility is equal to 55/45×100= 122.22

Have a good day. Hope it helps!!