Part A: A sample of P-32 with a half-life of 14.3 days has been observed for 14.3 days. How many half-lives have occurred during this time?
a) Three half-lives
b) One half-life
c) Two half-lives
d) It is not possible to determine from the given information.

Part B: A sample of Dy-165 with a half-life of 120 minutes has been observed for 360 minutes. What is the current state of the sample?
a) It has completely decayed.
b) It has undergone one half-life.
c) It has undergone two half-lives.
d) It is not possible to determine from the given information.