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 :
[tex]M+Y\geq 6.5.[/tex]
Condition B :
[tex]8M+5Y\leq40.[/tex]
Now, if she buys 4 gallons of milk, the the conditions become
[tex]4+Y\geq 6.5~~\Rightarrow Y\geq 2.5,\\\\8\times 4+5Y\leq 40~~\Rightarrow Y\leq 1.6.[/tex]
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).
