A metalworker has a metal alloy that is 20% copper and another alloy that is 65% copper. How many kilograms of each alloy should the metalworker combine to create 60 kg of a 47% copper alloy? The metalworker should use kilograms of the metal alloy that is 20% copper and ? kilograms of the metal alloy that is 65% copper. (Type whole numbers.)
