A metal worker has a metal alloy that is 20% copper and another metal alloy that is 60% copper.
How many kilograms (kg) of each alloy should the metal worker combine to create 80kg of a 52% copper alloy?
Let x be the amount of the 20% copper alloy.
Then the amount of the 60% copper alloy is 80 - x.
The amount of copper in the 20% alloy is 0.2x.
The amount of copper in the 60% alloy is 0.6(80 - x).
The total amount of copper in the final alloy is 0.52(80).
So we have the equation 0.2x + 0.6(80 - x) = 0.52(80).
Simplifying the equation gives 0.2x + 48 - 0.6x = 41.6.
Combining like terms gives -0.4x + 48 = 41.6.
Subtracting 48 from both sides gives -0.4x = -6.4.
Dividing both sides by -0.4 gives x = 16.
So the metal worker should combine 16 kg of the 20% copper alloy and 80 - 16 = <<80-16=64>>64 kg of the 60% copper alloy. Answer: \boxed{16, 64}.