Answer:
a) 4 1/10 slices eaten
b) cannot be solved because we don't know how many slices in each pizza
Step-by-step explanation:
5*1/10=5/10
12*3/10=36/10
36/10+5/10=41/10
41/10=4 1/10 slices
3-----4
3-----4
3-----4
Total (Left): 9
Total (Right): 12
-------------------
Total (Left) + Total (Right) = 9 + 12 = 21