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

### Instruction:
Nancy can hula hoop for 10 minutes.  Casey can hula hoop 3 minutes less than Nancy.  Morgan can hula hoop three times as long as Casey.  How long can Morgan hula hoop?

### Response:
Nancy can hula hoop for 10 minutes.
Casey can hula hoop 3 minutes less than Nancy, or 10-3=<<10-3=7>>7 minutes.
Morgan can hula hoop three times as long as Casey, or 3*7=<<3*7=21>>21 minutes.
#### 21

