Question

A total of $9000 is invested: part at 5% and the remainder at 15%. How much is invested at each rate if the annual interest is $520?

Answer 1

$8300 at 5% and $700 at 15% is invested to get annual interest $520

Using Linear Equation:

Here we will use system of linear equation in two variable to solve this. We will use M and N variable for the amount invested. We know the total amount invested is $9000. So we can say that:

M + N = $9000       -------------(i)

We also know that 5% of one of the investments and 15% of the remaining money is equal to $520. So we can say:

0.05M + 0.15N = $520         ---------- (ii)

now, from equation - (i) M = 9000 - N put value of M in equation (ii)

we get,

0.05 ( 9000 - N ) + 0.15N = $520

0.1N = $70

N = $700

put value of N in any equation to get the value of M:

M = $9000 - N

M = $9000 - $700

M = $8300

Hence, $8300 at 5% and $700 at 15% is invested to get annual interest $520

Learn more about "Linear Equation" from here: https://brainly.com/question/19569110

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