Methuselah lived 782 years after he became the father of Lamech, and he had other sons and daughters.
When Methuselah had lived 187 years, he became the father of Lamech.
The entire lifetime of Methuselah was 969 years, and then he died.
The length of time Adam lived after he became the father of Seth was 800 years; during this time he had other sons and daughters.