Answer:
Betsy will save $121 in 5 weeks.
Step-by-step explanation:
We can see that Betsy's savings are 3 times the saving of her last week. We can see that this is an geometric sequence as 1,3,9,..
To find the sum of our geometric sequence we will use
, where n is number of terms we are taking sum of, a is first term of sequence and r is common ratio of the sequence.
![S_{5}=1\cdot \frac{1-3^{5}}{1-3}](https://tex.z-dn.net/?f=S_%7B5%7D%3D1%5Ccdot%20%5Cfrac%7B1-3%5E%7B5%7D%7D%7B1-3%7D)
![S_{5}=\frac{1-243}{-2}](https://tex.z-dn.net/?f=S_%7B5%7D%3D%5Cfrac%7B1-243%7D%7B-2%7D)
![S_{n}=\frac{-242}{-2}=121](https://tex.z-dn.net/?f=S_%7Bn%7D%3D%5Cfrac%7B-242%7D%7B-2%7D%3D121)
Therefore, Betsy will save $121 in 5 weeks.
Answer:
1.732050808
Step-by-step explanation:
7(p)
p=3
7(3)
the answer is 21.
Answer:
11
Step-by-step explanation:
1/3 nr^2h = volume of a cone
1/3 x 22/7 x 14 x r^2 = 440
r^2 = 440 x 3 x 7/22 x 1/14
r^2 = 30
r = 30
r = 5
Answer:
sorry kid idontknow
Step-by-step explanation: