Volume = 1/3 pi r^2 h
= 1/3 * 10^2 *81 pi
= 2700 pi units^3
Its C
You would use unit rate for this. If Austin makes $209 in 11 hours, then he makes 209/11 = 19 dollars in 1 hour.
Then, we can make a proportion:
$19/1 hour = $152/ x hours
Cross multiply:
152 = 19x
Solve for x to get:
x = 8 hours.
The answer is a. increase energy efficiency. This means that we now use less energy to do more thanks to many advances in technology. It could also be due to the use of alternative sources of power such as the sun or win. These new sources provide energy without causing pollution.
tbh google