dreamv wrote:On a scale that measures the intensity of a certain phenomenon, a reading of n+1 corresponds to an intensity that is 10 times the intesity corresponding to a reading of n. On that scale, the intensity corresponding to a reading of 8 is how many times as great as the intensity corresponding to a reading of 3?

A. 5
B. 50
C. 10^5
D. 5^10
E. 8^10 - 3^10

Reading of n+1 corresponds to an intensity that is 10 times the intesity corresponding to a reading of n means every number on the scale is 10 times the previous number.
So, we can say that f(n + 1) = 10 * f(n)
Let us assume that the intensity corresponding to a reading of 3 be X, then f(3) = X
So, f(4) = 10 * f(3) = 10X
f(5) = 10 * f(4) = 10² * f(3)
f(6) = 10^3 * f(3) and so on
Hence, f(8) = 10^5 * f(3)

The correct answer is C.