Answer:
0.5981 = 59.81% probability that three or less of the selected adults have saved nothing for retirement
Step-by-step explanation:
For each adult, there are only two possible outcomes. Either they save nothing for retirement, or they save something. The probability of an adult saving nothing for retirement is independent of any other adult. This means that the binomial probability distribution is used 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.
20% of adults in the United States save nothing for retirement (CNBC website).
This means that 
Suppose that sixteen adults in the United States are selected randomly.
This means that 
What is the probability that three or less of the selected adults have saved nothing for retirement?
This is:

In which






0.5981 = 59.81% probability that three or less of the selected adults have saved nothing for retirement
(a) without replacement:
P(S)=13/52=1/4
P(SS)=(1/4)*(12/51)=1/17
Probability of selecting two spades without replacement is 1/17.
(b) with replacement
P(S)=13/52=1/4
P(SS)=(1/4)(13/52)=1/16
Probability of selecting two spades with replacement is 1/16.
Answer:
340 degrees
Step-by-step explanation:
So the key thing here is to notice that we are given the circumference which will allow us to find a value for the radius of the circle and hence the angle subtended by the arc (the central angle).
So the circumference of a circle = 2pi(r)
This means:
6 = 2pi(r)
Which means that
r = 6/2pi or r = 3/pi
Now we can use this value of r to find our angle in conjunction with the value of the arc length. So:
Arc length is defined by: length = θr
Where θ is our angle value.
So lets plug in:

Multiply by pi to get:

Divide by 3 to get that:
θ = 17pi/9
So if we convert that from radians to degrees we get 340 degrees.
Step-by-step explanation:
5×6'3n=20
30'3n=20
3n=20-30
3n/3= -10/3
n= -3