For a certain cylinder, the diameter equals the height. If every length in this cylinder is decreased by 60%, then to the nearest integer, by what percent does the volume decrease?
Choose the correct choice.
A) 22%
B) 40%
C) 60%
D) 84%
E) 94%
Again, the exact dimensions of the cylinder do not matter, as long as every length increases by the same percent or same ratio. We now have a percent decrease, which means we subtract to construct our multiplier. A 60% decrease means we have a multiplier of 1 – 0.60 = 0.4, and so k = 0.4 as well. For volume we need to cube the scale factor: k^3 = (0.4)^3 = 0.064 {approx} 0.06 approximately. That would be the multiplier for a 94% decrease, because 1 – 0.94 = 0.06; therefore, the volume decreases by 94%. Answer = 94%.
<result>E</result>
For a certain cylinder, the diameter equals the height. If every length in this cylinder is decreased by 60%, then to the nearest integer, by what percent does the volume decrease?