Mel is three years younger than Katherine.  When Katherine is two dozen years old, how old will Mel be in years? Let's think step by step and output the final answer after "####".
user
When Katherine is 2 dozen years old, she will be 2*12=<<2*12=24>>24 years old.
If Mel is three years younger than Katherine, then when Katherine is 24 years old, Mel will be 24-3=<<24-3=21>>21 years old.
#### 21
Mel is three years younger than Katherine.  When Katherine is two dozen years old, how old will Mel be in years?
train