Were Shem, Cham (Ham), and Yaphet (Japheth) born the same year?

Answer From The Annual Reading Schedule - Week 1 Notes For Genesis: No. Although Genesis 5:32 says they were born when Noach (Noah) was 500 years old, we learn that this is generalizing about Noach's age when the sons were born, not giving an exact age for all three. This is shown by Genesis 10:21 which states Yaphet (Japheth) was the elder brother and Genesis 11:10 which states Shem was 100 years old 2 years after the flood, and the flood happened when Noach was 600 when the flood waters came (Genesis 7:6). This shows that Noach was actually 502 when Shem was born.