Jewish commentaries (Jewish Publication Society, for example) explain how there are these and other places in scripture where there are different accounts, one after the other, or even interwoven. The story of the flood seems to be three different accounts interwoven.
The wrong way to read the Bible is to treat it as a science textbook, which the Catholic Church says, too. We should be looking for religious truth that bears on our salvation.
So much of Bible expertise was developed in those early chapters of Genesis, but all throughout scripture, as well.
The Jewish scholars postulate that, in this case, two main verbal traditions of creation were accepted as valid and incorporated into the text, not wanting to lose anything that they already considered to be inspired.
The Catholic Church (here,
ewtn.com/library/CURIA/PBCJWSCR.HTM) says that the Hebrew Scriptures – what we commonly refer to as The Old Testament – ARE a part of the Bible [the heretic Marcion wanted to throw out the OT]. And, this document also says that the gospels and the new testament don’t even make sense without the Old Testament, up to and including Genesis.
I’ve seen a book or two from JPS discussing these “contradictions,” The Jewish scholars throughout history have taken the position of always trying to harmonize the apparently contradictory verses. I think it’s safe to say that is the Catholic position, as well.
I’ll say what might become obvious from reading a lot of Bible commentaries, no one has found that the New Testament fusses over these issues. For sure, endless discussion has taken place over the four gospels which do not agree in every detail. This problem of contradictions does not “go away” once you get to the New Testament.
And, there’s more. The Hebrew version of the Old Testament that the Jews accept as most authoritative is the Masoretic text, whereas the New Testament clearly is based on a knowledge of the Greek translation of the OT, called the Septuagint (which was also composed by Jews).
THIS IS why the Catholic Church has a “magisterium” established by Christ, to sort out and teach the true gospel message. Jesus said that whoever hears the Church, hears him. Nothing could make the issue clearer that that, but of course Protestants disagree and don’t even believe very strongly in the idea of “church,” anyway.
But you need not bother about their flawed ideas/perceptions of biblical/theological matters.