I think it's a pretty common question when people are thinking about homeschooling- how much time spent teaching? How much time doing book work?
It's not quite up there with the questions about socialization but it is a big concern, and one that people ask for a few reasons.
First, there are the people who think that homeschoolers are never doing enough- that by the very nature of homeschooling it's never sufficient. It's usually pretty easy to suss out if this is the reason that people are asking and that no matter what you say they are going to fault you. If your kids are doing poorly it's because you aren't doing enough and if they are doing well they'd be doing better if you did more. This would also be the, "There's no right answer" people.
There are people who are just being polite. Homeschooling is obviously a big part of a homeschooler's life, so asking about it is natural. They probably don't want a lot of nitty gritty details, though, but it can be a good opportunity to plant some seeds about homeschooling.
There are people who know someone homeschooling, have seen it on the news, or have other casual exposure to the ideas. They are probably genuinely curious and wondering how it pulls together, and if everyone does it the same way (we don't!).
There are the people who are homeschooling themselves, or considering it. These are my favorite people to talk homeschooling to, because less time is spent in apologetics and more in shop talk.
No matter the reason for asking, it's a tough question to answer. How much time?
It depends what you count.
Does Sweet Pea's reading time count? She spends about 2-3 hours a day reading books, some by her own choice, some that I've suggested because they match with science or history.
Does art and project time count? Time spent with an instrument?
I think what most people want to know is how much time is direct instruction in a typical subject and how much time it takes to chug through all the subjects for the day. It's still a variable answer, but it's a little easier to pin down for me.
We spend about 2-3 hours a day on Sweet Pea's school. This does not include reading, homework, helping around the house, art, or anything like that. I'm not personally in the camp of counting every little thing we do as school, although lots of valuable learning happens outside the books we use.
Right now the biggest chunks of our day go to math and language arts. How it divides up really changes by the day and Sweet Pea's cooperation, but my general goal is to be done with the important stuff by lunch so she can spend the afternoon reading, doing legos, playing, ect.
This might not seem like a long school day (or maybe it seems really long!) but we accomplish a lot. Sweet Pea is on level or ahead in all current subject areas with this amount of work, so it's a good balance for right now!
Little Bird spends significantly less time on school and as soon as she feels done we are done. In this time I try to do a little phonics and a little math. Otherwise I read to her. The rest of her day is play time.
I hope this helped a little with the scope of how long school takes.