Answer to what? I’m confused lol
The way you put it is confusing. I'll answer but the way you put it was confusing to me.

just to clarify the engineering notation, E6 is just 1 and 6 zeros, or a million, thus, 107,000,000 is just 107E6.
The answer is B
15 L of pure water must be mixed with 10 L of a 25% acid solution to reduce it to a 10% acid solution
Answer:

Step-by-step explanation:
This scenario can be modeled using an exponential growth equation.
The exponential growth equations have the following form:

Where P is the population in year t
p is the initial population at t = 0
r is the growth rate
t is the time in years.
In this case we know that the current population is 13,000 and that the growth rate is 11%
So

The equation that models this scenario is:

