Answer:
The number of key rings sold on a particular day when the total profit is $5,000 is 4,000 rings.
Step-by-step explanation:
The question is incomplete.
<em>An owner of a key rings manufacturing company found that the profit earned (in thousands of dollars) per day by selling n number of key rings is given by </em>
<em />
<em />
<em>where n is the number of key rings in thousands.</em>
<em>Find the number of key rings sold on a particular day when the total profit is $5,000.</em>
<em />
We have the profit defined by a quadratic function.
We have to calculate n, for which the profit is $5,000.

We have to calculate the roots of the polynomial we use the quadratic equation:

n1 is not valid, as the amount of rings sold can not be negative.
Then, the solution is n=4 or 4,000 rings sold.