At what temperature do KCL and KNO3 have the same solubility

If a saturated solution of KNO3 at 20.0 C is heated to 80.0 how much more could be dissolved?

If a saturated solution of KCL at 90.0 C is colled to 30.0 C how much of the solid will precipitate?

How much NaCL will dissolve in 350.0 g of water at 70.0C

How much KCL Will dissolve in 50. g of water at 50.0C

What mass of O2 can be dissolved in 2000.0 g of water at 30.0 C

Please help me work these out. I am doing a practice page before my test 2morrow and I need to know how to work them THANKS