Mandy is 3 years old. Her brother is 4 times as old as she is. Her sister is 5 years younger than her brother.  What is the age difference between Mandy and her sister? Let's think step by step and output the final answer after "####".
user
Mandy's brother's age is 3 years x 4 = <<3*4=12>>12 years old.
Her sister's age is 12 years - 5 years = <<12-5=7>>7 years old.
The age difference between Mandy and her sister is 7 years - 3 years = <<7-3=4>>4 years.
#### 4
Mandy is 3 years old. Her brother is 4 times as old as she is. Her sister is 5 years younger than her brother.  What is the age difference between Mandy and her sister?
train