Q: "One boy skateboarding on a rail and three boys watching." Does this mean that "The boys are outside"?
A: yes

Q: "Two young boys running down an upper level breezeway." Does this mean that "The young boys are wearing hoodies"?
A: it is not possible to tell

Q: "There are three swimmers from the same team getting ready to compete." Does this mean that "The three teammates get ready for the swim meet."?
A: yes

Q: "Two people hike up a snowy hill." Does this mean that "Two people walking up a snowy hill."?
A:
yes