Puzzle time - the church quilt

[jon-nyc]

You come along just as a church raffle is closing; its prize is a quilt worth $100 to you, but they've only sold 25 tickets. At $1 a ticket, how many tickets should you buy?

[jon-nyc]

(Suspend disbelief about a quilt being worth $100 if you need to)

[taiwan_girl]

There are unlimited tickets?

[Klaus]

||-75||

OK, it's the other maximum. But I don't want to spoil it yet. I know that @George-K is also a big fan of these puzzles, hence I'll leave him the chance to answer first.

Seriously, guys and gals: This isn't hard! There's one step that requires a little bit of math background if you want to "solve" it, but one can just as well skip that step and try a few values to find the solution.

[Copper]

My wife works with a quilting group that raffles the quilts for thousands, although usually it is hundreds. It's all for charity, mostly for needy children and they also make pillows used in ICUs.

[mark]

If it's worth a $100 to you, then buy 100 tickets, you cheap bastard! lol

[jon-nyc]

@taiwan_girl said in Puzzle time - the church quilt:

There are unlimited tickets?

Sure.

[jon-nyc]

Klaus's wrong answer offers me evidence that he knows the right one.

[Axtremus]

||Expected return is ($100N/(N+25))-$1N where N is the number of tickets you buy. Find the N that gives you the maximum value for 100N/(N+25)-N . N=25.||

[Axtremus]

Pad with another post because the index page actually displays part of the content in spoiler.

[Klaus]

Come on, Ax. Show us that you can properly derive that thing and find its zeros.