Answer:
Ordering a soft drink is independent of ordering a square pizza.
Step-by-step explanation:
20% more customers order a soft drink than pizza, therefore they cannot be intertwined.
Given: P(A)=0.5 & P(B)=.7
P(A∩B) = P(A) × P(B)
= 0.5 × .7
= 0.35
P(A∪B) = P(A) + P(B) - P(A∩B)
= 0.5 + .7 - 0.35
= 0.85
P(AΔB) = P(A) + P(B) - 2P(A∩B)
= 0.5 + .7 - 2×0.35
= 0.5
P(A') = 1 - P(A)
= 1 - 0.5
= 0.5
P(B') = 1 - P(B)
= 1 - .7
= 0.3
P((A∪B)') = 1 - P(A∪B)
= 1 - 0.85
= 0.15
Answer:
The probability that all three have type B+ blood is 0.001728
Step-by-step explanation:
For each person, there are only two possible outcomes. Either they have type B+ blood, or they do not. The probability of a person having type B+ blood is independent of any other person. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
The probability that a person in the United States has type B+ blood is 12%.
This means that 
Three unrelated people in the United States are selected at random.
This means that 
Find the probability that all three have type B+ blood.
This is P(X = 3).


The probability that all three have type B+ blood is 0.001728
The two-way table is attached.
There are 58 people. 31 do not play baseball; this means that 58-31=27 do play baseball.
16 people play football; this means 58-16=42 people do not play football.
20 people do not play football or baseball; 42-20 = 22 people play baseball but do not play football.
27-22=5 people play baseball and football.
16-5=11 people play football but do not play baseball.