Which of the following sulfates is insoluble in water?

The condition for the function $f(x)=x^3+p x^2+q x+r$ $(x \in R)$ to have no extreme value is

Two spheres of equal masses,one of which is a thin spherical shell and the other a solid sphere,have the same moment of inertia about their respective diameters. The ratio of their radii will be

Which of the following statements is incorrect?

$\int_0^1 x^{3/2} \sqrt{1-x} \, dx$ is equal to