How long did the Israelite's dwell in Egypt 430 years or 215 years?

the idea that the children of Israel lived in Egypt for 430 years is mathematically incorrect. If we carefully study the timeline, we find that the Bible makes a serious mistake in calculating the length of time dwelt in Egypt by the Children of Israel.

Exodus 7:7 Moses was 80 years old

Exodus 6:20 Amram was 137 years old

Exodus 6:17 Kohath was 133 years old

Genesis 46:11 Kohath was the son of Levi when they went to Egypt genesis 46:26 with Jacob

Let’s assume   Kohath was a new born baby when he went to Egypt. And let’s assume Amram was born the year his father passed away, and let’s assume Moses was born the year his father passed way

133 + 137 + 80 = 350

Which means, the amount of the spent in Egypt would have been no longer than 350 years maximum. Now more than likely Amaram was not a baby when he arrived to Egypt, and it's more than likely Kohath was not born the year his father passed away, and it’s more than likely Moses was not born the year his father passed way.

this means the amount of time spent in Egypt would have been significantly less than 350 years. so why does Exodus 12:40 say the time Israelites spent in Egypt was 430 years?

Now the length of time the Israelite people lived in Egypt was 430 years. (Exodus 12:40)

in one of the letters of Paul to Galatians we read:

This is what I am trying to say: The agreement God made with Abraham could not be canceled 430 years later when God gave the law to Moses. God would be breaking his promise. (Galatian 3:17)

Basically, what Paul is saying from the time Abraham received his promise to the time Moses received his law there was 430 years.

Let’s do the maths

Abraham received the promise when he entered Canaan when he was 75 Genesis 12:3-5,7. then 25 years later when Abraham was 100 years old, that’s when Isaac was born Genesis 21:5. then 60 years later when Isaac was 60 years old, that’s when Jacob was born Genesis 25:26. then a 135 years later when Jacob was 130 years old that’s when all of Israel arrived in Egypt Genesis 47:9.

So add 25 + 60 + 130 = 215 which means there’s 215 years from the time that Abraham entered Canaan to the time all of Israel arrived in Egypt

Now Moses received the law the same time they left Egypt, so Paul is saying there was 430 between Abraham and Moses. And according to the Old Testament there is 215 between Abraham and Jacob entering Egypt.

So take 430 and subtract 215 and that equals to 215 years, which means the amount of time the Israelites were in Egypt was 215 years. (215 in Egypt 215 in Canaan) 430 total.

Now that's mathematically possible.

Flavius Josephus a 1st century Jewish Historian mentions:

"they left Egypt…four hundred and thirty years after out forefather Abraham came into Canaan, but two hundred and fifteen years only after Jacob removed into Egypt" (Josephus Antiquities of the Jews 2.15.2)

What even more interesting is the Samaritan Pentateuch says

Now the sojourning of the children of Israel and fathers of them, who dwelt in Canaan and in Egypt, [was] four hundred and thirty years. (Exodus 12:40 Samaritan Torah) This means the Masoretic Torah was altered (corrupted) by the scribes to received it and dropped out Canaan. Unless you disagree with the Samaritan Torah? The other problem seems to point at the God of the Old Testament, who was corrected by Paul and Flavius Josephus.