Decay of radioactivity

I have 10000000000 Bq (bequerel) of I-123 in 2 cc of saline on Monday at 8 Am
a) What is the concentration at 8Am
b) What volume should I inject on Monday at 8Am if I wish to inject 40 Mbq
c) What volume should I inject on Tuesday at 8AM if I wish to inject 60 MBq
d) After the injection on Tuesday, what activity of I-123 is left?