Four cups of a salad blend containing 40% spinach is mixed with an unknown amount of a salad blend containing 55% spinach. The resulting salad contains 50% spinach. How many cups of salad are in the resulting mixture? 8 9 12 13

To solve this problem, we need to set up an equation based on the given information.<br /><br />Let's denote the unknown amount of the salad blend containing 55% spinach as x cups.<br /><br />The total amount of spinach in the resulting mixture is equal to the sum of the amount of spinach in the 4 cups of salad blend containing 40% spinach and the amount of spinach in the x cups of salad blend containing 55% spinach.<br /><br />The amount of spinach in the 4 cups of salad blend containing 40% spinach is 4 * 0.40 = 1.6 cups.<br /><br />The amount of spinach in the x cups of salad blend containing 55% spinach is 0.55x cups.<br /><br />The total amount of spinach in the resulting mixture is 0.50 * (4 + x) cups.<br /><br />So, we can set up the equation:<br /><br />1.6 + 0.55x = 0.50 * (4 + x)<br /><br />Now, let's solve this equation step by step:<br /><br />1.6 + 0.55x = 2 + 0.50x<br />0.05x = 0.4<br />x = 8<br /><br />Therefore, the resulting mixture contains 4 + 8 = 12 cups of salad.<br /><br />The correct answer is 12.