They were all contemporariness. Adam and Eve had Seth the same time all these people were living in Nod.
Gen 4:16-26
(16) And Cain went out from the presence of the LORD, and dwelt in the land of Nod, on the east of Eden.
(17) And Cain knew his wife; and she conceived, and bare Enoch: and he builded a city, and called the name of the city, after the name of his son, Enoch.
(18) And unto Enoch was born Irad: and Irad begat Mehujael: and Mehujael begat Methusael: and Methusael begat Lamech.
(19) And Lamech took unto him two wives: the name of the one was Adah, and the name of the other Zillah.
(20) And Adah bare Jabal: he was the father of such as dwell in tents, and of such as have cattle.
(21) And his brother's name was Jubal: he was the father of all such as handle the harp and organ.
(22) And Zillah, she also bare Tubalcain, an instructer of every artificer in brass and iron: and the sister of Tubalcain was Naamah.
(23) And Lamech said unto his wives, Adah and Zillah, Hear my voice; ye wives of Lamech, hearken unto my speech: for I have slain a man to my wounding, and a young man to my hurt.
(24) If Cain shall be avenged sevenfold, truly Lamech seventy and sevenfold.
(25) And Adam knew his wife again; and she bare a son, and called his name Seth: For God, said she, hath appointed me another seed instead of Abel, whom Cain slew.
(26) And to Seth, to him also there was born a son; and he called his name Enos: then began men to call upon the name of the LORD.