College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 32

The identical twins Speedo and Goslo join a migration from Earth to Planet X, which is 20.0 light-years away in a reference frame in which both planets are at rest. The twins, of the same age, depart at the same time on different spacecraft. Speedo's craft travels steadily at 0.950 c , Goslo's at 0.750 c. Calculate the age difference between the twins after Goslo's spacecraft lands on Planet X. Which twin is the older