When you study this Old Testament timeline you will see that Noah and the grandson of Adam lived together for 84 years. They may have had time for a tea or coffee together :-).
And Noah lived 58 years together with Abraham. They may have had tea or coffee together also! Who knows?
What we know is that it is not a big tradtion line from the creation until Abraham and Moses, although a lot of time has passed since creation. So they knew definetly with certainty what happened when.