This is an exponential equation that can be represented by the following:
f(x) = a(b)^x
In this case...
25143 = a(0.66)^3
25143 is the population after 3 hours.
3 is the amount of time in hours.
0.66 represents the percent of the population remaining after each hour (66% as there is a 34% decline each hour).
We must solve for a, which is the initial population.
First, simplify (0.66)^3 to 0.2874.
25143 = 0.2874a
Now divide both sides by 0.2874 to isolate a.
a = 87455
There were initially 87,455 people within the city. I wouldn't want to be in that place!
10% is the correct answer to this question
Derek would have planted the tree 7 years ago. You subtract 36 from 44.75 and get 8.75. This is how much the tree grew since he planted it. Then, you'll divide 8.75 by 1.25 (1 1/4) which tells you how many years it has been since he planted the tree. The final answer is 7 years. Hope this helps!