Question

Two investments totaling $21,000 produce an annual income of $870. One investment yields 4% per year, while the other yields 10% per year. How much is invested at each rate?

Answer 1

Answer:

The amount invested at 4% is $20,500 and the amount invested at 10% is $500

Step-by-step explanation:

Let

x -----> the amount invested at 4%

(21,000 -x) ----> the amount invested at 10%

we know that

The interest of the amount invested at 4% plus the interest of the amount invested at 10% must be equal to $870

$4\%=4/100=0.04$

$10\%=10/100=0.10$

so

$0.04(x)+0.10(21,000-x)=870$

Solve for x

$0.04x+2,100-0.10x=870$

$0.10x-0.04x=2,100-870$

$0.06x=1,230$

$x=\ 20,500$

$21,000-x=\ 500$

therefore

The amount invested at 4% is $20,500 and the amount invested at 10% is $500