According to the Genesis 11, Terah was the son of Nahor, who was the son of Serug, who was the son of Reu, who was the son of Peleg, who was the son of Eber, who was the son of Shelah, who was the son of Arpachshad, who was the son of Shem, who was the oldest son of Noah.
According to Genesis 11 Terah had three sons, Abram, Haran, and Nahor; according to Genesis 20:12 Sarah, Abraham's wife, was his half-sister (i.e., the daughter of Terah by a wife other than the mother of Abraham). He lived in "Ur of the Chaldees," where his son Haran died, leaving behind his son Lot. Nahor settled at Haran, a place on the way to Ur. Terah afterwards migrated with Abraham (probably his youngest son) and Lot (his grandson), together with their families, from Ur, intending to go with them to Canaan; however he stayed in Harran, where he died at the age of two hundred and five years (Genesis 11:24-32). Following his death, Abram moved his family out of Haran. (Acts 7:4) The Book of Joshua reports that Terah worshiped other gods. (Josh. 24:2.)
The Bible has been accused that Terah's age when he fathered Abram, the age of Abram when he left Haran, and the age of Terah at his death contradict one another and bring the consistency of the entire text of the Torah into question. One author of this encyclopedia claimed this:
The Torah's account of Terah's life presents some problems regarding the consistency of the text as a whole. He is represented as fathering Abram (Abraham) at the age of seventy, and dying at the age of 205. Abraham should therefore be 135 at the time of Terah's death, yet according to Genesis 12:4 he is only 75.
A close look at Genesis reveals that this logic is based on the assumption that Abram was fathered when Terah was 70 years of age.
Genesis 11:26 says "And Terah lived seventy years, and begat Abram, Nahor, and Haran."
The counter-argument is that Abram, Nahor and Haran were not triplets. They may have been different ages, and Terah fathered the oldest of the three at age 70. Then, assuming that the ages are accurate, Abram is not the oldest of the three. He was probably mentioned first because he was of the most importance to the messianic line. As the middle or youngest child, Abram would have been conceived when Terah was 130.
With this very simple explanation, the Torah does not necessarily contradict itself regarding the ages of Terah and Abram.