how old would you be, when you returned from a trip while traveling at 99.5% C if your relatives that stayed at home, were 10 years older?

Question

how old would you be, when you returned from a trip while traveling at 99.5% C if your relatives that stayed at home, were 10 years older?

Answer 1

The apparent "slowing down factor", γ is

1/√(1-0.995²)
=1/.0998
=10.01

So if you went on a trip of a year in your frame of reference, your relatives would think that you've gone for 10 years.