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
Rational numbers can be written as a fraction
the last two ones be the same, the outcomes would be TTT,HTT,THH,HHH
so the probability is 4/8 = 1/2.
If 
, then 
and 
because 
lies in the fourth quadrant.
By DeMoivre's theorem,
so the answer is B.
The length is: 42 inches
The width is : 21 inches
