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

### Instruction:
 德克兰的大儿子和小儿子的年龄差为10岁。如果大儿子现在40岁，小儿子30年后多少岁？


### Response:
 如果大儿子现在40岁，小儿子就是40-10 = <<40-10=30>>30岁。
30年后，小儿子将会是30+30 = <<30+30=60>>60岁。