Flight training hour requirements

[jjsemperfi]

So I'm embarrassed to ask this question but I guess I've never really understood this. So for a Part 141 Private Course there is a minimum of 35 hours flight training. Then broken down there is 20 hours from a CFI that includes 3 hrs x-county, 3 hrs night that includes one x-country of more than 50 nm total distance with 10 take offs and landings in the pattern at an airport, and 3 hours in prep for the practical within 60 days.... bla bla bla. So, my question is... is that 15 hour difference between the 20 hours with the CFI and the 35 total solo, x-cnty, hour building time? I just think it's weird how they don't mention anything about that 15 hours. Like I said, I'm really embarrassed because I should know this stuff, but I guess I have always just trusted my instructors to just tell me how many hours I need and I just focused on flying and not the endorsements and the hours. Also, I know there are ways to combine that flight time such as performing that those 3 hours of night during a x-country of more than 50 nms and doing the 10 take offs and landings....etc... Am I correct on this? If you can't tell, I'm studying endorsements, hour requirements, private and commercial add on's and it's making my head spin.

[zippiesdrainage]

The way it's broken down is that there have to be at least a total of 35 hours. Of those 20 have to be with an instructor and 5 have to be solo. The remainder is 10 hours. The regulations show the minimums since we know that nobody can actually learn to fly a helicopter and be ready to go for a checkride at 35 hours. The FAA also recognizes and lists these hours for non-traditional students. Since some students may have a friend/family member with a helicopter they can get some flight time in. That way even the (lucky) students who have a friend with a helicopter can't simply ride along for 35 hours and say that they're ready for a checkride, they can only actually use 10 of those hours from their friend toward their rating, thereby making everyone (hopefully) happy.