One hundred thirty kilograms of sludge containing 38% solute and 62% inerts is mixed with a solvent in a single stage leaching operation. The suspension is allowed to settle, and the overflow and underflow are separated. The underflow has 0.85 kg solution retained per kg inerts. It the recovery of the solute in the overflow is 86%, calculate (a) the concentration (in mass fraction) of solute in the underflow (b) the concentration (in mass fraction) of the solute in the overflow if its free from solids (c) the mass of solvent needed (d) the total mass of overflow and underflow.