This is Giant Adventure Comics 2, published by Mimosa (SA Magazine Co) +/- 1962.
It reprints the cover and all three stories from DC Comics' Adventure Comics 280 (1960):
"Superboy and the Mermaid from Atlantis"
"The Seven Faces of Congorilla"
"The Lost Ocean"
Also reprinted is this story from DC Comics' Adventure Comics 234 (1957):
"1,001 rides with Superboy"
Also reprinted is this story from DC Comics' Adventure Comics 193 (1953):
Grren Arrow: "The three shots that Green Arrow missed!"
48pages, glossy colour cover, black and white newsprint interior.
Here is the cover of issue 2 and DC Comics' original cover: