Answer:
36.36% probability that she gave birth to quadruplets
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcoes.
Desired outcomes:
Giving births to quadruplets.
She has 4 sets of quadruplets.
So 
Total outcomes:
At least 3 children(triplets).
7 sets of triplets and 4 sets of quadruplets.
So 
Probability:

36.36% probability that she gave birth to quadruplets
We have a domain of a function, that is, which x-es can we throw in. But we are asking which y-s will we get given that we can only throw x-es in
.
Let's try
even though we are forbidden to put 4 inside
we are still able to do so.
So
what we just got is the upper limit of the range. The lower limit is
.
So the range is just
.
Hope this helps :)
Answer:
The difference in amount = $430
Step-by-step explanation:
1- Annual contract:
The annual contract means a contract for 12 months. There is a month penalty for breaking the lease.
This means that, if you left after 8 months, you will have to pay for 10 month.
Total paid = monthly payment * 10
Total paid = 535 * 10 = $5350
2- Month-to-month contract:
You will only paid for the 8 months you stayed,
Total paid = monthly payment * 8
Total paid = 615 * 8 = $4920
3- Getting the difference:
We can note that a month-month contract is a better option if you intend to stay for only 8 months
Difference = 5350 - 4920 = $430
Hope this helps :)
Is that the exact question? because the last part doesn't really make sense to me
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Answer: 16
Step-by-step explanation: