inferences from the graph and list solutions to avoid mixed fractions

Q$\mathrm{.}3($b$)$ Determine the settling velocity of $60m$ & $10$ mm particles in a fluid of density $1\mathrm{.}2k\frac{g}{m^3}$ for two conditions: $($i$)$ free settling of particles $($ii$)$ settling velocity of fine particle if settling of one particle affects settling of another. Particle Density $=1280k\frac{g}{m^3}$ and viscosity of fluid $=1\mathrm{.}8{10}^{-5}N\frac{s}{m^2}.$

question $3($b$)$