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

### Instruction:
 乔恩的教科书比布兰登的教科书重三倍。乔恩有四本教科书，分别重2、8、5和9磅。布兰登的教科书重多少磅？


### Response:
 乔恩的教科书总共重2 + 8 + 5 + 9 = <<2+8+5+9=24>>24磅。
因此，布兰登的教科书重24 / 3 = <<24/3=8>>8磅。