Answer: The answer is (D). Zhao Xue doesn’t have enough money left to buy any yofurt
Step-by-step explanation: Given that Zhao Xue is buying buy milk and yogurt, a total of at least 6.5 gallons of dairy products and she has a budget of $20. The given graph represents the constraints on the number of gallons of milk 'M' and yogurt 'Y' Zhao Xue buys. Zhao Xue buys 4 gallons of milk. We need to calculate the number of gallons of yogurt she can buy to meet both her constraints.
From the graph, we can write
Condition A :
Condition B :
Now, if she buys 4 gallons of milk, the the conditions become
Here, there will be no solution to these constraints.
Therefore, she does not have enough money left to buy any yogurt.
Thus, the correct option is (D).