The answer is 21.73684211
Perimeter = 93 x 2 + 63 x 2 = 186 + 126 = 312 feet
So 400,000 DVD sales with a 31% decline means in the 1st year following, there will be a decline of 124,000 DVDs sold. So we need to take 400,000 - 124,000, which equals a starting point for year two is 276,000 DVDs.
So a 31% decline on 276,000 = 85,560. So we need to subtract that from 85,560 from 276,000 which is 190,440. So at the end of the second year, DVD sales were only 190,440. That's also out starting point of the 3rd year.
So 31% of 190,440 equals 59,036.4 for the third year of DVD sales. So we need to subtract 59,036.4 from out third year starting point of 190,440, which equals 131,403.6, but since you can't have parts of DVDs, we'll round the decimal point fraction to a whole number to end up with 131,404 DVDs sold in year three.
So after three years of a 31% yearly decline in DVD sales you end up with DVD sales are 131,404
The first thing any good mathematician does is convert the measurements to the same unit as what the question is asking. In this problem, it states that the pool fills at a rate of 20 cubic meters per hour. Just keep in mind that an hour is 60 minutes.
The next step is to see how many cubic meters will cost $300. This can be done by dividing 300 by 10. This gets you 30 cubic meters of water.
You already know that 60 minutes is 20 cubic meters of water. That leaves the remaining 10 cubic meters of water. By dividing the rate given, you get that 30 minutes is 10 cubic meters of water. Add the 60 and 30 together to get 90 minutes.
It will take 90 minutes for the pump to use $300.
Answer:
2.92
Step-by-step explanation:
![V=\frac{4}{3}\pi r^3 \\ \\ 105=\frac{4}{3}\pi r^3 \\ \\ r^3=\frac{105}{\frac{4}{3}\pi} \\ \\ r=\sqrt[3]{\frac{105}{\frac{4}{3}\pi}} \\ \\ r \approx 2.92](https://tex.z-dn.net/?f=V%3D%5Cfrac%7B4%7D%7B3%7D%5Cpi%20r%5E3%20%5C%5C%20%5C%5C%20105%3D%5Cfrac%7B4%7D%7B3%7D%5Cpi%20r%5E3%20%5C%5C%20%5C%5C%20r%5E3%3D%5Cfrac%7B105%7D%7B%5Cfrac%7B4%7D%7B3%7D%5Cpi%7D%20%5C%5C%20%5C%5C%20r%3D%5Csqrt%5B3%5D%7B%5Cfrac%7B105%7D%7B%5Cfrac%7B4%7D%7B3%7D%5Cpi%7D%7D%20%20%5C%5C%20%5C%5C%20r%20%5Capprox%202.92)
