Mark the cranberry justice as x. Then, he needs x oz cranberry juice, 2x oz orange juice and 8x oz ginger ale. Then make the following equation:
[tex]x + 2x + 8x = 176 \\ 11x = 176 \\ x = 176 \div 11 \\ x = 16[/tex]
He needs x=16 oz cranberry juice, 2x=32 oz orange juice and 8x=128 oz ginger ale.