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

### Instruction:
 瑞秋比莉大4岁。如果他们的年龄总和是34岁，瑞秋多大？


### Response:
 如果瑞秋和莉的年龄相同，那么他们的年龄总和将是34 - 4 = 30岁。
所以莉的年龄是30/2 = 15岁。
这意味着瑞秋的年龄是15 + 4 = 19岁。