The pulp density formula gives: C = P (Pp-1) Pp (P-1) Where Cs is the solids concentration by mass, ps is the solids specific gravity, pp is the pulp specific gravity. Measurement of a thickener feed gives: C = 0.2095, ps= 2.65, pp = 1.15 If the error in measuring ps and pp is 0.02, what is the error in Cs? Here measurement "error" may mean the precision with which one can read density on a Marcy scale.