Which is the simplified form of the expression

The ksp expression for the system pbcl2(s) pb+2(aq) + 2 cl-(aq) is: [pbc12][pb+2][2cl-] [pb+2][cl-]2 [pb+2][2cl-]2 [pbcl2][pb+2][cl-]2 [pb+2][2cl-]2[pbcl2]

When a valve is open 281 gallons of water go through it in one hour the number of gallons that would go through in 94 hours is

What is the solution for 6 - 7/8? explain the steps.