.
Ramesh earns 5% on a $7,500 investment compounded annually. How long will it take for the investment to reach $50,000?
Compound yearly formula: f(t) = a × (1+b)^t
~~~~~~~~~~~~~~~~~~~~
So, what you need is to solve this inequality for time " t " in years
>= 50000.
It is equivalent to the inequality
>=
or
>= 6.66667
To solve it, take logarithm base 10 of both sides. You will get
t*log(1.05) >= log(6.66667),
or
t >= = use your calculator = 38.88 years.
You must round it to the closest greater integer number in order for the bank was in position to make the last compounding.
So your final ANSWER is 39 years.
Solved.
-------------------
To see many similar solved problems with all detailed explanations (your TEMPLATES), look into these two lessons
- Compound interest percentage problems
- Problems on discretely compound accounts
in this site, and learn the subject from there.
After reading these lessons, you will tackle such problems on your own without asking for help from outside.
Also, you have this free of charge online textbook in ALGEBRA-I in this site
- ALGEBRA-I - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Logarithms".
Save the link to this online textbook together with its description
Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson
to your archive and use it when it is needed.
Happy learning (!)