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

### Instruction:
James spends 40 years teaching.  His partner has been teaching for 10 years less.  How long is their combined experience?

### Response:
His partner has been teaching for 40-10=<<40-10=30>>30 years
So their combined experience is 30+40=<<30+40=70>>70 years
#### 70