Answer:
0.4 ml
Explanation:
The mother solution contains 10 mCi, but the patient just need 4 mCi.
So using a rule of three, it would be:
10 mCi - 1 ml
4 mCi - X X = (4x1) /10 = 0.4 ml
And considering the half life of 6 hours, need to pass 18 h to have a dose in the body that is insignificant. (at the first 6 h it will have 2 mCi, at the next 6 hours 1mCi, at the next 6 hours 0.5 mCi)
So it would be 0.4 ml of the mother solution every 18 h.
