## Elementary Algebra

Let X represent the amount of grapefruit in the mixture. Since the first mixture is 30 ounces and the second mixture is 50 ounces, the resulting mixture will be 30 + 50 = 80 ounces. To find X, the amount of grapefruit in the mixture, we use the following guideline: Amount of grapefruit in the first solution + amount of grapefruit in the second solution = Amount of grapefruit in the final solution. 10% $\times$ 30 + 20% $\times$ 50 = X $.1 \times 30 + .2 \times 50 =X$ 3 + 10 = X X = 13 There are 13 ounces of grapefruit in the 80 ounce mixture. Since we need to calculate the percentage of grapefruit juice, we proceed: $\frac{13}{80}$ $\times$ 100% = 16.25%