Decathalon
The Nordic combined event is still a men only event. All other events women are allowed and permitted to compete in.
The only event was the 190 meter spint
Synchronised swimming
The first Summer Olympic games had only nine events. Today there are over 25 events in the Summer Olympics. Some of those events include polo, swimming, diving, track, and volleyball.
Team sprint in track cycling
Summer event that are co-ed are Equestrian only
The Ancient Olympic Games consisted of only one race, the "stade" race
No, only ice hockey and field hockey are.
Relay events.
Heptathlon, Synchronised Swimming and one other
I only know one and that's baseball.