Answer:
Allison = $0.27
Brianna = $1.89
Step-by-step explanation:
The total cookies that the three girls have are:
Allison's cookies + Brianna's Cookies
= 9+15
=24
There is a total of 24 cookies which has to be divided between the 3.
So
Each girl gets 24/3 = 8 cookies.
Since Celeste had no cookies she will have to pay for the 8 cookies.
Allison had 9, she will give one to Celeste
Brianna had 15 out of which she will use 8 for her self and 7 will be given to Celeste.
Celeste is paying 2.16 for 8 cookies.
Price of one cookie = 2.16/8
=$0.27
So, amount that will be given to Allison = 0.27 * 1 = $0.27
Amount that will be given to Brianna = 0.27 * 7 = $1.89
Answer:
b. A binomial variable with 25 independent trials
Step-by-step explanation:
The conducted experiment is binomial experiment because outcome can be divided into success or failure. The success would be the people who read novel in the past year and also responses are independent of each other. We have to find the number of trials n in the given problem.
we are given that variance of R=6 and p=probability of success=0.4.
We know that variance of binomial distribution is
Variance=npq
where q=1-p=1-0.4=0.6.
By putting the values in variance formula, we can get the value of n.
6=n*0.4*0.6
6=0.24*n
n=6/0.24
n=25
Hence, random variable R is a binomial variable with 25 independent trials.
Answer:
8978 grams
Step-by-step explanation:
The equation to find the half-life is:

N(t) = amount after the time <em>t</em>
= initial amount of substance
t = time
It is known that after a half-life there will be twice less of a substance than what it intially was. So, we can get a simplified equation that looks like this, in terms of half-lives.
or more simply 
= time of the half-life
We know that
= 35,912, t = 14,680, and
=7,340
Plug these into the equation:

Using a calculator we get:
N(t) = 8978
Therefore, after 14,680 years 8,978 grams of thorium will be left.
Hope this helps!! Ask questions if you need!!