A 45 -gallon bathtub is to be filled with water that is exactly 105^{\circ} F. Unfortunately, the two sources of water available are 120^{\circ} F and 60^{\circ} F. When mixed, the temperature will be a weighted average based on the amount of each water source in the mix. How much of each should be used to fill the tub as specified?

Amount of 120

Amount of 60

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