Consider the milling circuit of a tin ore shown in Figure $3.$ Determine the following:

$1.$ The circulating load ratio;

$2.$ The percentage solid of the pulp in the ball mill discharge;

$3.$ The volumetric flowrate of the sump water addition;

$4.$ A nuclear density gauge is fitted on the pipe of the hydro cyclone feed. What will be the value indicated by this instrument?