21:39
PMA's? Actually, five in all. (But I sort of cheated. I sponsor a Math Club at a local high school; we meet monday, thursday, and saturdays when theirs a math competition or such. Some of the students have very wealthy parents, but three of the students I'm working with (14, 14, 15) have already passed AP Calculus, but their parents have little money to supplement their kids education, beyond the public schools. So yesterday, I gave them each a copy of PMA (behind the scenes).
...and added the text to the "club's" syllabus, ensuring that if they are unable to purchase a copy, I'd make sure, somehow, that they would have one available to them.
I also gave a copy, to two eighth-grade students who love mathematics, to hold onto, so once they've encountered calculus, they can explore.