'One's' in the Bible

I know that there is nothing better for them than to rejoice and to do good in one’s lifetime;

Here is what I have seen to be good and fitting: to eat, to drink and enjoy oneself in all one’s labor in which he toils under the sun during the few years of his life which God has given him; for this is his reward.

A good name is better than a good ointment,And the day of one’s death is better than the day of one’s birth.