Stephen, in his speech which led to him being stoned to death stated that 75 people went to join Joseph in Egypt.

Act 7:14  Then Joseph sent and called his father Jacob and all his relatives to him, seventy-five people.
Act 7:15  So Jacob went down to Egypt; and he died, he and our fathers.

But in three different places in the Old Testament, (Genesis, Exodus, and Deuteronomy) it states that 70 people when down to Egypt.

Gen 46:27  And the sons of Joseph who were born to him in Egypt were two persons. All the persons of the house of Jacob who went to Egypt were seventy.

Exo 1:1  Now these are the names of the children of Israel who came to Egypt; each man and his household came with Jacob:
Exo 1:2  Reuben, Simeon, Levi, and Judah;
Exo 1:3  Issachar, Zebulun, and Benjamin;
Exo 1:4  Dan, Naphtali, Gad, and Asher.
Exo 1:5  All those who were descendants of Jacob were seventy persons (for Joseph was in Egypt already).

Deu 10:22  Your fathers went down to Egypt with seventy persons, and now the LORD your God has made you as the stars of heaven in multitude.

How can these two numbers, 70 and 75, be reconciled? 

Genesis 46

Wee need to look at the account in Genesis 46 which gives a lot more detail.

Gen 46:8  Now these were the names of the children of Israel, Jacob and his sons, who went to Egypt: …

The following verses all the way through to verse 27 list Jacob’s sons and their children. 

Leah’s sons

First in the list are Jacob’s 6 sons from Leah.

Gen 46:8  … Reuben was Jacob’s firstborn.
Gen 46:9  The sons of Reuben were Hanoch, Pallu, Hezron, and Carmi.
Gen 46:10  The sons of Simeon were Jemuel, Jamin, Ohad, Jachin, Zohar, and Shaul, the son of a Canaanite woman.
Gen 46:11  The sons of Levi were Gershon, Kohath, and Merari.
Gen 46:12  The sons of Judah were Er, Onan, Shelah, Perez, and Zerah (but Er and Onan died in the land of Canaan). The sons of Perez were Hezron and Hamul.
Gen 46:13  The sons of Issachar were Tola, Puvah, Job, and Shimron.
Gen 46:14  The sons of Zebulun were Sered, Elon, and Jahleel.
Gen 46:15  These were the sons of Leah, whom she bore to Jacob in Padan Aram, with his daughter Dinah. All the persons, his sons and his daughters, were thirty-three.

Summarising we have:
5 – Reuben plus his 4 sons
7 – Simeon plus his 6 sons
4 – Levi plus his 3 sons
6 – Judah plus his 5 sons (Er and Onan are not included)
5 – Issachar plus his 4 sons
4 – Zebulun plus his 3 sons
1 – Dinah

Only 5 sons of Judah are counted.  Er and Onan are not included because they died in the land of Canaan (Genesis 46:12).

This gives a total of 32.  But Genesis 46:15 says there were 33.  This number of 33 must include Jacob.  This becomes apparent when the summary is given in Genesis 46:26-27, (see the section “All of the sons” below).

Zilpah’s sons

Next in the list are Jacob’s 2 sons from Zilpah.

Gen 46:16  The sons of Gad were Ziphion, Haggi, Shuni, Ezbon, Eri, Arodi, and Areli.
Gen 46:17  The sons of Asher were Jimnah, Ishuah, Isui, Beriah, and Serah, their sister. And the sons of Beriah were Heber and Malchiel.
Gen 46:18  These were the sons of Zilpah, whom Laban gave to Leah his daughter; and these she bore to Jacob: sixteen persons.

Summarising we have:
8 – Gad plus his 7 sons
8 – Asher plus his 7 sons

This gives a total of 16 for the 2 sons of Zilpah their sons.

Rachel’s sons

Next in the list are Jacob’s 2 sons from Rachel.

Gen 46:19  The sons of Rachel, Jacob’s wife, were Joseph and Benjamin.
Gen 46:20  And to Joseph in the land of Egypt were born Manasseh and Ephraim, whom Asenath, the daughter of Poti-Pherah priest of On, bore to him.
Gen 46:21  The sons of Benjamin were Belah, Becher, Ashbel, Gera, Naaman, Ehi, Rosh, Muppim, Huppim, and Ard.
Gen 46:22  These were the sons of Rachel, who were born to Jacob: fourteen persons in all.

Summarising we have:
3 – Joseph plus his 2 sons
11 – Benjamin plus his 10

This gives a total of 14 for the 2 sons of Rachel their sons.

Bilhah’s sons

Next in the list are Jacob’s 2 sons from Bilhah.

Gen 46:24  The sons of Naphtali were Jahzeel, Guni, Jezer, and Shillem.
Gen 46:25  These were the sons of Bilhah, whom Laban gave to Rachel his daughter, and she bore these to Jacob: seven persons in all.

Summarising we have:
2 – Dan plus his son
5 – Naphtali plus his 4 sons

This gives a total of 7 for the 2 sons of Bilhah their sons.

All of the sons

Adding up the numbers in the preceding verses we get: 33 + 16 + 14 + 7 = 70. 

Gen 46:26  All the persons who went with Jacob to Egypt, who came from his body, besides Jacob’s sons’ wives, were sixty-six persons in all.
Gen 46:27  And the sons of Joseph who were born to him in Egypt were two persons. All the persons of the house of Jacob who went to Egypt were seventy.

The total of 66 persons clearly excludes Jacob as the 66 are those who “came from his body”.  It also excludes Joseph and his 2 sons as they were already in Egypt.  The number 66 comes from 70 less Jacob, Joseph, and Joseph’s 2 sons.

70 persons

From this detailed account in Genesis 46 we see that 70 persons of the house of Jacob went to live in Egypt.  This number includes Jacob, all his 12 sons and 1 daughter, and all his grandsons.  But it explicitly excludes his son’s wives (Genesis 46:26).

This is corroborated by both Exodus 1:5 and Deuteronomy 10:22.

75 persons

What about Acts 7:14 which mentions 75 people?

Act 7:14  Then Joseph sent and called his father Jacob and all his relatives to him, seventy-five people.

Where did Stephen get this number of 75 from?  As we’ve seen, Genesis 46:26, Exodus 1:5, and Deuteronomy 10:22 all give a number of 70.  Did Stephen have some special knowledge or revelation from God?  Or was it something that was commonly accepted?  Stephen spoke before the religious council, directly to the high priest.

Act 6:15  And all who sat in the council, looking steadfastly at him, saw his face as the face of an angel.
Act 7:1  Then the high priest said, “Are these things so?”
Act 7:2  And he said, “Brethren and fathers, listen: …

In his speech, Stephen quoted from Scriptures many times, to make his point.  In quoting 75 as the number, was this something new to his audience that would confuse them, or something his audience was familiar with?  The latter makes more sense.

It seems that Stephen got this figure of 75 from the Septuagint, which was widely used at the time of Jesus Christ.  (The Septuagint is a Greek translation of the Old Testament .)  Genesis 46:27 in the Septuagint reads.

Gen 46:27 And the sons of Joseph, who were born to him in the land of Egypt, were nine souls; all the souls of the house of Jacob who came with Joseph into Egypt, were seventy-five souls. [Septuagint]

Compare this with the standard text.  The important differences are in bold.

Gen 46:27  And the sons of Joseph who were born to him in Egypt were two persons. All the persons of the house of Jacob who went to Egypt were seventy. [NKJV]

It turns out that the Septuagint is different in several places.  Here is a table which highlights the differences between the NKJV and the Septuagint in how the numbers are broken down.

NKJV	Septuagint
Gen 46:15  These were the sons of Leah, whom she bore to Jacob in Padan Aram, with his daughter Dinah. All the persons, his sons and his daughters, were thirty-three.	15 These the sons of Lea, which she bore to Jacob in Mesopotamia of Syria, and Dina his daughter; all the souls, sons and daughters, thirty-three.
Gen 46:18  These were the sons of Zilpah, whom Laban gave to Leah his daughter; and these she bore to Jacob: sixteen persons.	18 These the sons of Zelpha, which Laban gave to his daughter Lea, who bore these to Jacob, sixteen souls.
Gen 46:19  The sons of Rachel, Jacob’s wife, were Joseph and Benjamin. Gen 46:20  And to Joseph in the land of Egypt were born Manasseh and Ephraim, whom Asenath, the daughter of Poti-Pherah priest of On, bore to him. Gen 46:21  The sons of Benjamin were Belah, Becher, Ashbel, Gera, Naaman, Ehi, Rosh, Muppim, Huppim, and Ard. Gen 46:22  These were the sons of Rachel, who were born to Jacob: fourteen persons in all.	19 And the sons of Rachel, the wife of Jacob; Joseph, and Benjamin. 20 And there were sons born to Joseph in the land of Egypt, whom Aseneth, the daughter of Petephres, priest of Heliopolis, bore to him, Manasses and Ephraim. And there were sons born to Manasses, which the Syrian concubine bore to him, Machir. And Machir begot Galaad. And the sons of Ephraim, the brother of Manasses; Sutalaam, and Taam. And the sons of Sutalaam; Edom. 21 and the sons of Benjamin; Bala, and Bochor, and Asbel. And the sons of Bala were Gera, and Noeman, and Anchis, and Ros, and Mamphim. And Gera begot Arad. 22 These the sons of Rachel, which she bore to Jacob; all the souls eighteen.
Gen 46:25  These were the sons of Bilhah, whom Laban gave to Rachel his daughter, and she bore these to Jacob: seven persons in all.	25 These the sons of Balla, whom Laban gave to his daughter Rachel, who bore these to Jacob; all the souls, seven.
Gen 46:26  All the persons who went with Jacob to Egypt, who came from his body, besides Jacob’s sons’ wives, were sixty-six persons in all. Gen 46:27  And the sons of Joseph who were born to him in Egypt were two persons. All the persons of the house of Jacob who went to Egypt were seventy.	26 And all the souls that came with Jacob into Egypt, who came out of his loins, besides the wives of the sons of Jacob, all the souls were sixty-six. 27 And the sons of Joseph, who were born to him in the land of Egypt, were nine souls; all the souls of the house of Jacob who came with Joseph into Egypt, were seventy-five souls.

The first divergence occurs in the sons of Rachel, Genesis 46:19-22.  The Septuagint adds Machir (Manasseh’s son), Galaad (Manasseh’s grandson), Sutalaam (Ephraim’s son), Taam (Ephraim’s son), Edom (Ephraim’s grandson) and misses Huppim (Benjamin’s son) to get 18 rather than 14.

The second divergence occurs in the final total.  The Septuagint says 75 rather than 70.  But the Septuagint is not even self-consistent; adding its numbers: 33 + 16 + 18 + 7 = 74, but it gives 75.

Furthermore, the Septuagint is not consistent in the figure it gives in Exodus and Deuteronomy.

Exodus 1:5 But Joseph was in Egypt. And all the souls of Jacob were seventy-five.  [Septuagint]

Deuteronomy 10:22 With seventy souls your fathers went down into Egypt; but the Lord thy God has made thee as the stars of heaven in multitude.  [Septuagint]

Conclusion

The obvious conclusion is that the Septuagint is not very reliable.  The correct figure for the number of people of Jacob’s household who went to Egypt is 70.

But how do we explain Acts 7:14?  Stephen quoted an inaccurate figure from the Septuagint.  He probably wasn’t aware it was inaccurate, but now this inaccurate figure is in the Bible!  That’s not a problem.  The Bible accurately records what Stephen spoke.  It makes no comment on the accuracy of all his words.