We will see that her expected profit is -$5.
We define profit as the difference between the revenue and the costs.
In this case, we know that she expects to sell 20 cups of lemonade for $1 each, so the expected revenue would be:
20*$1 = $20.
And we also know that her costs are $10 for a sign and $15 for materiales, so the total cost is:
$10 + $15 = $25
Finally, the profit would be:
P = revenue - cost = $20 - $25 = -$5
So she has a negative profit.
If you want to learn more about profit, you can read:
https://brainly.com/question/19104371