Answer:
21 pieces of chickens.
Step-by-step explanation:
Given:
The farmer has a total of 40 animals. ( cows and chicken )
He counts the legs of all his animals and realizes he has a total of 118 legs.
Question asked:
How many chickens does the farmer have ?
Solution:
Let number of chickens = 
Then number of cows = 
Now, as here given that total number of legs are 118 of all the animals, and as we know that a chicken has two legs and cow has four legs, hence the equation will be :
<u>Total number of legs = Number of legs having chickens + Number of legs having cows</u>


Subtracting both sides by 160

By adding both sides by minus

By dividing both sides by 2

Hence, farmer have 21 pieces of chickens.
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
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