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

### Instruction:
 布伦达比梅尔的体重多10磅，是梅尔体重的3倍。如果布伦达体重为220磅，梅尔的体重是多少？


### Response:
 假设梅尔的体重为m
布伦达的体重是3*m +10 = 220磅
因此3m=220-10
3m=210
梅尔的体重是m=210/3
梅尔的体重是m=70磅