Answer: Since her art and music sections each only had half the number of sheets of paper as a core subject, together the two sections had the same amount of paper as a core subject. Therefore, it is almost like her notebook had five core subjects, rather than four core subjects and two electives. If she divided the 200 sheets equally among the five core subjects, there would be 200 ÷ 5 = 40 sheets in each section. Now we can see that art would actually have half of this amount, or 20 sheets of paper.
Answer:
We are given that According to government data, 75% of employed women have never been married.
So, Probability of success = 0.75
So, Probability of failure = 1-0.75 = 0.25
If 15 employed women are randomly selected:
a. What is the probability that exactly 2 of them have never been married?
We will use binomial
Formula : 
At x = 2
b. That at most 2 of them have never been married?
At most two means at x = 0 ,1 , 2
So, 
c. That at least 13 of them have been married?
P(x=13)+P(x=14)+P(x=15)
For there to be 1 car, we consider two possible outcomes:
The first door opened has a car or the second door opened has a car.
P(1 car) = 2/6 x 4/5 + 4/6 x 2/5
P(1 car) = 8/15
For there to be no car in either door
P(no car) = 4/6 x 3/5
P(no car) = 2/5
Probability of at least one car is the sum of the probability of one car and probability of two cars:
P(2 cars) = 2/6 x 1/5
= 1/15
P(1 car) + P(2 cars) = 8/15 + 1/15
= 3/5
