You invested $4000 between two accounts paying 2% and 6% annual interest,respectively.if the total interest earned for the year was $120, how much was invested at each rate

Answer 1

Hi Sabrina

We are given the total Principal of 4000 dollars and the total interest earned for the year of 120 dollars.

We can start with two equations and two unknowns then use Substitution to solve the problem

Let x = amount invested at 2% interest annually

Let y = amount invested at 6% interest annually

For the total principal we have Equation 1

x + y = 4000

so, y = 4000-x

For the total interest earned we have

Equation 2

.02x + .06y = 120

You can substitute for y and put everything in terms of x to solve the problem

0.02x + .06(4000-x) = 120

Can you continue and solve x first then use that data to find y.

I get $3000 at 2% and $1000 at 6%

Remember you can use the equations above to check.

I hope this helps.