Answer:
a) About 12%
Step-by-step explanation:
We need to find the interest rate required to achieve her goal, so we will need to use the interest-compound formula:
Where:
PV= Present Value
i= interest rate
FV= Future Value
n= number of periods
replacing the data provided:
solving for i:
first, divide both sides by 50.000 to simplify the equation:
Take 
roots of both sides:
±![\sqrt[10]{3}](https://tex.z-dn.net/?f=%5Csqrt%5B10%5D%7B3%7D)
solve for i:
±![\sqrt[10]{3} -1](https://tex.z-dn.net/?f=%5Csqrt%5B10%5D%7B3%7D%20-1)
We get two answers, but we look for a coherent value. So we take the positive one:
≈12
I will rewrite the question for better understanding:
Ashley recently opened a store that uses only natural ingredients. She wants to advertise her products by distributing bags of samples in her neighborhood. It takes Ashley 2/3 of a minute to prepare one bag. It takes each of her friends 75% longer to prepare a bag. How many hours will it take Ashley and 4 of her friends to prepare 1575 bags of samples?
Answer:
- <em><u>5.3 hours</u></em>
Explanation:
<u>1) Time it takes Ashley to preprate one bag: </u>
<u>2) Time it takes each friend of Ashley: 75% more than 2/3 min</u>
- 75% × 2/3 min = 0.75 × 2/3 min = 3/4 × 2/3 min= 2/4 min = 1/2 min = 0.5 min
- 2/3 min + 1/2 min = 7/6 min
<u>3) Time it takes Ashley and the 4 friends working along to prepare one bag:</u>
- Convert each time into a rate, since you can set that the total rate of Ashley along with her four friends is equal to the sum of each rate:
- Rate of Ashley: 1 bag / (2/3) min = 3/2 bag/min
- Rate of each friend: 1 bag / (7/6) min = 6/7 bag/min
- Rate of Ashley and 4 friends = 3/2 bag/min + 4 × 6/7 bag/min = (3/2 +24/7) bag/min = 69/14 bag/min
<u>4) Time of prepare 1575 bags of samples:</u>
- time = number of bags / number of bags per min = 1,575 bags / (69/14) bags/min = 319.56 min
<u>5) Convert minutes to hours:</u>
- 356.56 min × 1 hour / 60 min = 5.3 hours
Answer:
=(k−1)*P(X>k−1) or (k−1)365k(365k−1)(k−1)!
Step-by-step explanation:
First of all, we need to find PMF
Let X = k represent the case in which there is no birthday match within (k-1) people
However, there is a birthday match when kth person arrives
Hence, there is 365^k possibilities in birthday arrangements
Supposing (k-1) dates are placed on specific days in a year
Pick one of k-1 of them & make it the date of the kth person that arrives, then:
The CDF is P(X≤k)=(1−(365k)k)/!365k, so the can obtain the PMF by
P(X=k) =P (X≤k) − P(X≤k−1)=(1−(365k)k!/365^k)−(1−(365k−1)(k−1)!/365^(k−1))=
(k−1)/365^k * (365k−1) * (k−1)!
=(k−1)*(1−P(X≤k−1))
=(k−1)*P(X>k−1)
