I need some help answering these chemistry questions...?

Question

Hi, Im studying for a chemistry exam and these are some practice questions that I need help with...
1. For the compound calcium phosphate, Ca3(PO4)2, what is the total number of ions represented in the formula?
a)2
b)3
c)5
d)4
2. What is the molar mass of Barium Nitrate, Ba(NO2)3?
a)167.3 g/mol
b)199.3 g/mol
c)247.3 g/mol
d)261.3 g/mol
3. How can the solubility of a gaseous solute in a liquid solvent be increased?
a) increasing the volume of the mixing container
b) lowering the temperature of the solvent
c) decreasing the pressure on the liquid
d)Stirring vigorously

Answer 1

1. c) 5

2. d) 261.3

3. b) lowering the temperature of the solvent (think Coca Cola!)

Answer 2

one is c) 5 (3 calcium and 2 PO4)
two is not in the choices(its 275.35 g/mol)
for three, i want to say b