First find how old Bethany's sister currently is: 16 years - 5 years = <<16-5=11>>11 years

Then find how old her sister was 3 years ago: 11 years - 3 years = <<11-3=8>>8 years

Then double that age to find how old Bethany was three years ago: 8 years * 2 = <<8*2=16>>16 years

Then add 3 years to that number to find how old Bethany is now: 16 years + 3 years = <<16+3=19>>19 years

# Answer

19
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Three years ago, Bethany was twice the age of her younger sister. In 5 years, her younger sister will be 16. How old is Bethany now?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
19
Three years ago, Bethany was twice the age of her younger sister. In 5 years, her younger sister will be 16. How old is Bethany now?
train