Question

The function f(n)=100(0.25)^n represents the amount of radioactive substance left after n hours. At what rate in percent is the amount of radioactive substance changing

Answer 1

75%

Explanation:

Given the function :

f(n)=100(0.25)^n

Comparing the function with

y = a(1 - r)^t

From. The equation, r = rate

Comparing with the value in bracket in the question given :

1 - r = 0.25

1 - 0.25 = r

0.75 = r

Hence, r = 0.75

As a percentage, rate = 0.75 * 100% = 75%

Hence, the rate of change is 75%