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

### Instruction:
 玛丽亚有一支钢笔和一支铅笔。她买钢笔的价格是铅笔价格的一半。铅笔花了她8美元。玛丽亚一共付了多少钱买钢笔和铅笔？


### Response:
 钢笔的价格是铅笔价格的一半，所以它是8 * 0.5 = 4美元。
所以玛丽亚买钢笔和铅笔一共花了4 + 8 = 12美元。