Let BS be the event that the patient survives bypass surgery.
Let H be the event that the heart damage will heal.
Then P(BS) = 0.60, and also we have a conditional probability: GIVEN that the patient survives,
the probability that the heart damage will heal is 0.5, that is P(H|BS) = 0.5
We want to know P(BS and H).
Using the formula of the conditional probability:
P(H and BS) = P(H|BS)·P(BS) = (0.6)(0.5) = 0.3
I believe that the answer is C. Positive
You would divide 51 by 2 to get the answer, as the units are the same, for an answer of 25 two-thirds foot sized pieces, with 1 as a remainder.