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

### Instruction:
 一家便利店每周销售180加仑的苏打水。他们购买的糖浆盒可以制作30加仑的苏打水，每个盒子的成本是40美元。他们每周为糖浆支付多少钱？


### Response:
 他们需要购买180/30=<<180/30=6>>6个盒子
所以成本是6*40=$<<6*40=240>>240