How to understand "a family with three brothers"?
Born into a family with three brothers, David was brought up to value the sense of sharing.
Does "a family with three brothers" imply that the family has four boys or three boys?

Question

How to understand "a family with three brothers"?
Born into a family with three brothers, David was brought up to value the sense of sharing. 
Does "a family with three brothers"  imply that the family has four boys  or three boys?

Answer

It means he has three brothers and is the fourth.

Answer

That's actually a very good question! I've never thought about it before, but there could be some ambiguity there, couldn't there? Often it is worded thus - born into a family OF three brothers - which means three in total. I feel the author, by using  WITH, has introduced a lack of clarity. But I still assume the author means a total of three brothers. It's the 'family' with three brothers, not the man David with three brothers. I think! What do other people think? I'd like to know.

Answer

Yep, changed my mind... think it means 4 brothers!

Answer

Since it says "born into" I think it means he has three older brothers and he is the youngest boy. So there are four boys including David.