To calculate her commission on sales over $40,000, you need two key pieces of information:

1. The total sales amount: You should know how much in total she sold.
2. The commission rate: The percentage she earns as a commission for sales over $40,000.

Here’s how you can calculate it:

1. Subtract $40,000 from the total sales amount to find the portion over $40,000.

   $\text{Excess Sales} = \text{Total Sales} - 40,000$

2. Multiply the excess sales by the commission rate.

   $\text{Commission} = \text{Excess Sales} \times \text{Commission Rate}$

Do you know the total sales amount and commission rate? I can calculate it for you.

Would you like more details on this? Here are some related questions:

1. What happens if her sales were under $40,000?
2. Is there a different commission rate for sales under $40,000?
3. Does the commission rate increase after a certain amount?
4. Are there bonuses for exceeding a sales target?
5. How do commission structures differ by industry?

Tip: Always clarify whether the commission rate applies to the entire sales or just the portion above a certain threshold.