Final answer:
To make at least a $20 profit, Bernie needs to sell a minimum of 18 cups of lemonade, as selling 17 cups would not meet the required profit threshold.
Step-by-step explanation:
The student is asking how many cups of lemonade Bernie needs to sell to make a profit of at least $20. The inequality that represents Bernie's situation is 20 ≤ 1.50x - 6.50, where x is the number of cups sold. To find the number of cups Bernie must sell to break even and then make a $20 profit, we must solve for x in the inequality.
First, add $6.50 to both sides of the inequality to isolate the term involving x on one side:
20 + 6.50 ≤ 1.50x
26.50 ≤ 1.50x
Next, divide both sides by $1.50 to solve for x:
26.50 / 1.50 ≤ x
x ≥ 17.67
Since Bernie can only sell whole cups of lemonade, he must sell at least 18 cups to make a minimum of $20 in profit. Selling 18 cups will bring in $27 ($1.50 × 18), which after deducting the initial investment of $6.50, results in a profit of $20.50.