Answer:
"To the nearest year, it would be about 9 years"
Step-by-step explanation:
11c)
This is compound growth problem. It goes by the formula:

Where
F is the future amount
P is the present (initial) amount
r is the rate of growth, in decimal
t is the time in years
Given,
P = 20,000
r = 8% = 8/100 = 0.08
F = double of initial amount = 2 * 20,000 = 40,000
We need to find t:

To solve exponentials, we can take Natural Log (Ln) of both sides:

Using the rule shown below we can simplify and solve:

We can write:

To the nearest year, that would be about 9 years
Answer:
A is the answer
Step-by-step explanation:
You should pay attention to x^3 when you want to talk about infinite.
It would take 25 years for Birr 500 to quadruple if invested at a rate of 12% simple interest per annum.
<h3 /><h3>Simple interest formula</h3>
Using the simple interest formula A = P(1 + rt) where
- P = princial amount = Birr 500,
- A = final amount = 4P (since it is quadrupled),
- r = rate = 12% = 12/100 = 0.12 and
- t = time to quadruple
<h3 /><h3>Finding the time it takes to quadruple </h3>
Since we require t, making t subject of the formula, we have
t = [(A/P) - 1]/r
Substituting the values of the variables into the equation, we have
t = [(A/P) - 1]/r
t = [(4P/P) - 1]/0.12
t = [4 - 1]/0.12
t = 3/0.12
t = 25 years
So, it would take 25 years for Birr 500 to quadruple if invested at a rate of 12% simple interest per annum.
Learn more about simple interest here:
brainly.com/question/25793394