Answer:
The probability is 0.0428
Step-by-step explanation:
First, let's remember that the binomial distribution is given by the formula:
where k is the number of successes in n trials and p is the probability of success.
However, the problem tells us that when there isn't a number of trials fixed, we can use the geometric distribution and the formula for getting the first success on the xth trial becomes:

The problem asks us to find the probability of the first success on the 4th trial (given that the first subject to be a universal blood donor will be the fourth person selected)
Using this formula with the parameters given, we have:
p = 0.05
x = 4
Substituting these parameters in the formula and solving it, we get:

Therefore, the probability that the first subject to be a universal blood donor is the fourth person selected is 0.0428 or 4.28%
Im confused on what your trying to ask...
Answer:
70 cm^2
Step-by-step explanation:
The area of square is 5×10=50 plus the square of triangle, high of triangle is 18-10=8 and base of triangle is 5 because it common base with square, so the square of triangle is 1/2(8)(5)=20
The total area is 50+20=70 cm^2