Decide which person's amount to assign a variable. Follow the description and make expressions for each person. Form the necessary equation.
Pudge has three times as many apples as Ace, and Ace has twice as many as Christi.
Pudge 6c
Ace 2c
Christi c
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pudge has 12 more than both Ace and Christi together.
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Solve that for c and use it to find the quantities of Pudge and Ace.