Calculating total charge and charge on each sphere before and after they have touched each other

Three identical metal spheres, A, B, and C initially have net charges as shown. Spheres A and B are now touched together and then separated. Sphere C is then touched to sphere A and the separated from it. Lastly, sphere C is touched to sphere B and then separated from it. a) How much charge ends up on sphere C? What is the total charge on the three spheres? b) before they are allowed to touch each other and c) after they have touched?

sphere A= +5q
sphere B= -1q
sphere C= None

Since the spheres are metal and identical, each time two of the touch, the net charge on those two will be divided evenly between them.

Step 1: A and B, net chg +4q, divided evenly is +2q on each.

Step 2: A and C, net chg +2q, divided evenly is +1q on each.

Step 3: B and C, net chg +3q, divided evenly is +1.5q on each.

So, C ends up with +1.5q. The total charge before the process is +4q (5q - 1q + 0q), and since charge is conserved, you know it must still be +4q afterward, and indeed it is (1q + 1.5q + 1.5q).