Genesis 6:3 is a prediction of the timetable for the flood. Psalm 90:10 is simply stating that as a general rule, people live 70-80 years (which is still true today).
Mwanzo 6:3 ni utabiri wa ratiba kwa ajili ya mafuriko. Zaburi 90:10 inasema kwamba kama utawala kwa ujumla, watu huishi miaka 70-80 (ambayo bado ni kweli hii leo).