Table salt contains 5% impurities. How much is contained in 100 g of such an impurity.

Explanation of the solution: to find the mass of the impurity contained in the salt, you must use the formula: m (approx) = m (s) * w, where m (approx) is the mass of the impurity, m (c) is the mass of the salt that contains the impurities , w is the mass fraction of impurities in the salt, expressed in fractions, substituting the values, we get: m (approx) = m (s) * w = 100 * 0.05 = 5 g.