Homework Help: Math

Posted by CrissyXD on Saturday, March 24, 2012 at 4:46am.

Compound interest question:

When Aaron invested $100 at 4.5% p.a. annually compounding, it amounted to $142.21. For how many years was it invested?

Is there a way to solve this question without using the formula for compound interest?

Math - Reiny, Saturday, March 24, 2012 at 9:04am
You could repeatedly divide by 1.045 until you reach appr 100

e.g.
142.21/ 1.045 = 136.086 -- once
136.086/1.045 = 130.2256 --twice
....
109.20/1.045 = 104.50 -- 7 times
104.50/1.045 = 100 -- 8 times

so it took 8 years

Answer this Question

Related Questions

Math - A=P(1+r)^2 A= interest P= principle interest r= interest rate t= time in ...
Algebra - Compare the future amounts (A) you would have if the money were ...
continuous compounding? - $50,000 that was invested in 1970 was worth $134,100 ...
Algebra - Compare the future amounts (A) you would have if the money were ...
math - find the compound ammount $1000 at 6% compounded annually for 8 years Use...
math compound interest - I can figure all of the other compound interest ...
Math [Interest] - Okay, so I've been away from school for three weeks, and ...
Finance math - If $100 is invested at 6% compunded A - annually B - quarterly C...
Math! - A credit Union pays 8.25% comppunded annually on 5-year compound-...
maths - simple interest and compound interest on what sum will the compound ...

For Further Reading

First Name:
School Subject:
Answer: