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

### Instruction:
 约翰去商店买东西，用一张20美元的钞票付款。他买了3瓶苏打水，找回了14美元。每瓶苏打水的价格是多少？


### Response:
 他付了20-14=6美元。
所以每瓶苏打水的价格是6/3=2美元。