CGPET 2019 Solved Paper

The relation between solubility (S) and solubility product (KSP) is as follows
KSP=xx.y9.Sx+y
where, x and y are the number of atoms/radicals of the given species.
For M(OH)3 type species
x=1
y=3
thus, KSP=11×33S3+1=27S4
Hence, solution (d) is the correct answer.