Below is an instruction that describes a task. Write a response that appropriately completes the request in English. Please answer in English.

### Instruction:
Betty bought 1 kg of oranges and 3 kg of apples. The total cost of oranges was $12. The apples were two times cheaper than the oranges. How much did Betty pay for 1 kg of apples?

### Response:
The apples were two times cheaper than the oranges, so the cost of 3 kg of apples was 12 / 2 = $<<12/2=6>>6.
This means, that 1 kg of apples was a cost of 6 / 3 = $<<6/3=2>>2.
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