Question

Jane has $5000. She invests a portion of her money at a simple interest rate of 7% and the rest of her money at a simple interest rate of 6.2%. After one year, the total interest earned on these investments is $318.00. How much money did she invest at %7?

Answer 1

You need two equations.

Let x= the amout earning 7%; Let y= the amount earning 6.2%

Since the total invested is $5,000

then x+y=5,000

and the .07x+.062y=318

Rearrange the first equation so that y=5,000-x

Substitute into the second equation

So you have .07x+(.062)(5,000-x)=318

which simplifies to .008x=8

So x=1,000 dollars