Question

Which of the following functions represents an exponential growth of twenty-five percent?

A. f(x)=125(25)^x

B. f(x)= 15(2.5)^x

C. f(x)= 35(1.25)^x

D. f(x)= 2500(0.25)^x

Answer 1

The formula for exponential growth or decay is given by:

`y=ab^(x)`

where,

y=final amount,

a=initial amount,

b=rate of growth or decay,

x=number of times growth of decay occurs,

Two important points here are:

Percentage increase = 1+ rate of increase

Percentage decrease = 1-rate of decrease.

We are given exponential growth of 25%

Percentage increase = 1+0.25 = 1.25

Value of b is 1.25 here.

Answer: So correct choice will be option C . f(x) =(35)(1.25)ˣ

Answer 2

A 25% increase can be computed using a multiplier of 1 +25% = 1.25. The appropriate selection is ...
  C. f(x) = 35(1.25)^x