Interest rate for one year is rate percent amount of original investment. The amount invested by Mrs. Ming in the account paying 6% was $680
<h3>How to calculate interest after 1 year if the rate of interest is R% annually?</h3>
Suppose that annually there is interest rate of R%. The amount initially invested is P, then for 1 year, it doesn't matter if its simple or compounding annually, the interest is same (it doesn't remain same if compounding isn't annually or if the time is > 1 year)
The interest for 1 year will be 
Let we have the initial amount spent in account paying 8% interest rate as $x
Let for 6% interest paying account, initial amount was $y
Then, by the given data, we have:

and

Thus, we got a system of linear equations as :

From equation 1, getting value of x in terms of y, we get:

Substituting this value in second equation, we get:

Putting this value of y in the equation we got for x,

Thus, amount invested by Mrs Ming in account paying 8% interest rate as $x = $820
and for 6% interest paying account, initial amount was $y = $680
Thus,
The amount invested by Mrs. Ming in the account paying 6% was $680
Learn more about system of linear equations here:
brainly.com/question/13722693