an investment yields an annual interest of $1500. If $500 more is invested and the rate is 2% less, the annual interest is $1300. What is the amount of investment and the rate of interest?
Sounds like a job for some simultaneous equations.
Given A is the initial amount invested, r is the rate then
Maybe use
(1+r)A= 1500+A ...(1)
and
(A+500)(1+(r-2))=1300+(A+500) ...(2)
Leaves you with some algebra.
I may be over complicating this one, it is early morning here!
Hello, aeroflix!
An investment yields an annual interest of $1500.
If $500 more is invested and the rate is 2% less, the annual interest is $1300.
What is the amount of investment and the rate of interest?
Let $\displaystyle x$ = amount invested.
Let $\displaystyle r$ = rate of interest.
We are told that $\displaystyle x$ dollars at $\displaystyle r$ percent yields $1500.
. . Equation: .$\displaystyle rx \:=\:1500$
We are told that $\displaystyle (x+500)$ dollars at $\displaystyle (r-0.02)$ percent yields $1300.
. . Equation: .$\displaystyle (x+500)(r-0.02) \:=\:1300 $
Now solve the system of equations.
You will get a quadratic equation
and must discard one of the roots.