Question

A factory produces 1,250,000 toys each year. The number of toys is expected to increase by about 150% per year. Which model can be used to find the number of toys being produced, n (in millions), in t years?
A. n= 2.5(1.5)/t, t cannot = 0
B. n= 1.5t^2 + 1.25
C. n= 1.5t + 1.25
D. n= 1.25(2.5^t)

Answer 1

The answer is D. 
You multiply 1,250,000 by 1.50= 1,875,000
Then add 1,875,000 to 1,250,000= 3,125,000
Divide by 1,000,000 and you get 3.125

Answer 2

Answer: Hello mate!

The initial number produces is 1,250,000 toys per year, and you expect to increase by 150% per year.

an increase of 150% (1.5 in decimal form) means that after a year, the amount of toys produced are:

1,250,000 + 1.5*1,250,000 = 1,250,000*(1 + 1.5) = 1,250,000*2.5

and each year, you multiply the previous quantity by 2.5

then the model (in millions) is,  as a function of years:

p(0) = 1.25

p(1) = 1.25*2.5

p(2) = 1.25*2.5*2.5

and so on; you can see that:

p(t) = 1.25*(2.5^t)

So the right option is D.