Doubt From Ionic Equilibrium

See, illustration 17
How is Assertion and Reason both correct?
Please explain!

I will be thankful for help.

For saturated solution (At equilibrium) K_{sp}=Q (iconic product)
Also in the concepts K_{sp} is the max. Amount of the sparingly soluble salt that can be dissolved into a particular solvent.
Ksp is a constant for a solvent-solute pair at a constant Temp.

But,how assertion is true?
How Ksp is the maximum value of solute in a solution?

Because if you put less amount then it will be a unsaturated solution so you can add more salt then you reach Ksp value
If you add salt more than Ksp then precipitation process will happen and then it will again become saturated solution(neglect PPT)