Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The Ski Rental Problem

lesves.github.io

Post reply on HN
Print view View original

81–90 of 98 posts

Re: The Ski Rental Problem

#81

Post by bmacho »

lisbbb wrote: post #13

Oh man, I had no idea that the decision of whether to rent or buy skis required calculus to solve. I just figured that if you ski more than say, 3 times a season, it's probably better to own your own gear for reasons unrelated to the entry cost, but more to do with comfort, tuning, quality, and so on. Anyone who has rented skis knows that the rental fleets are trashed.

> Oh man, I had no idea that the decision of whether to rent or buy skis required calculus to solve.

The best decision is literally a bunch of equations that you want to solve / optimize. It is sometimes school level math, but that's rare.

Re: The Ski Rental Problem

#82

Post by andai »

prawn wrote: post #68
andai wrote: post #64

Earlier quoted context omitted.

This kind of blew my mind when I realized that if you buy second hand and resell, you can own a product (often for years) for net zero dollars. I was also delighted when I realized that instead of going through the hassle and cost of moving everything across the country, I could just sell it and buy roughly the same thing in the new place... again for net zero dollars! Teleportation!

I've seen this described as using Craigslist/similar for long term storage.

I read an article which described the free market as storage. People sell X when there is an oversupply and buy when there is an undersupply. The guy on the other end of those transactions acts as a storage provider.

Re: The Ski Rental Problem

#83

Post by saaaaaam »

SteveNuts wrote: post #27
Cerium wrote: post #23

Earlier quoted context omitted.

At least yours are in the garage. I have a friend who spent years storing a couple of hundred dollars of outdoor gear in a rental storage locker costing $50 per month.

I have relatives that have spent $60/mo for a storage unit for 12 years for some furniture they "might want to use some day if they buy a new house". Even pointing out that the furniture will likely look extremely dated by now and they've spent almost $10k so far doesn't seem to click at all.

I’ve just moved house. I have a few high quality pieces of furniture that I’d like to keep but don’t have space for, so considered storage. They are things that I’ve bought second hand and at auctions, and part of the pleasure is the hunt. So I felt I’d invested both money and time.

But then I realised that I can sell them for pretty much what I paid for them, put that money into a savings account or investments and buy them same things back in a few years. So that’s what I’m doing.

And, of course, I probably won’t buy the same things back in a few years. If I do then I’ll have all the pleasure of the hunt again. Or maybe I buy something else. Or maybe I just have the cash sitting and I can count my gold, Smaug style.

But either way I won’t have spent thousands on storage.

That realisation was extremely liberating.

Re: The Ski Rental Problem

#84

Post by unixhero »

jedberg wrote: post #41
massung wrote: post #15

This feels very similar to the “radio” or “restaurant” problem: You’re driving down the street trying to decide which restaurant to stop at (or scanning through the radio trying to decide which song to stop on). If you stop at the first, there’s a good chance something better is ahead. But if you wait too long then you risk getting stuck with something you don’t really like (the problem assumes you can’t go back). If…

Some would say this advice applies to finding a spouse as well. Date 37 people and keep track of the best. Then marry the next one that's better. :)

Marry the next one that tangents the best experienced after 37 (or other optimal number).

Re: The Ski Rental Problem

#85

Post by theoreticalmal »

david422 wrote: post #72
massung wrote: post #15

This feels very similar to the “radio” or “restaurant” problem: You’re driving down the street trying to decide which restaurant to stop at (or scanning through the radio trying to decide which song to stop on). If you stop at the first, there’s a good chance something better is ahead. But if you wait too long then you risk getting stuck with something you don’t really like (the problem assumes you can’t go back). If…

> I have the same issue every year with a ride on lawn mower. Do I just pay someone weekly or buy one outright and do it myself? In this case I loathe mowing, I bought mine, ran great for 4 years, then ran into a bunch of trouble, which made me recognize the other hidden cost of ownership is simply just maintenance. A very expensive mower just sitting there, nearest potential repair shop far away, no idea how I'd eve…

I just scrapped an ICE mower for a battery powered one. No more winterizing, changing oil, or worrying about filling with gas. I still don’t like mowing, but it sucks a little less now

Re: The Ski Rental Problem

#86

Post by IncreasePosts »

theoreticalmal wrote: post #85
david422 wrote: post #72

Earlier quoted context omitted.

> I have the same issue every year with a ride on lawn mower. Do I just pay someone weekly or buy one outright and do it myself? In this case I loathe mowing, I bought mine, ran great for 4 years, then ran into a bunch of trouble, which made me recognize the other hidden cost of ownership is simply just maintenance. A very expensive mower just sitting there, nearest potential repair shop far away, no idea how I'd eve…

I just scrapped an ICE mower for a battery powered one. No more winterizing, changing oil, or worrying about filling with gas. I still don’t like mowing, but it sucks a little less now

Sure, but you're just deferring moderate yearly maintenance cost for a rig that will need to be totally overhauled in 5 years due to battery degradation with current battery tech offered in mowers

At least, that's the conclusion I came to this year when researching ride-on battery mowers vs ICE. Electric push mowers seem like a no brainer though

Re: The Ski Rental Problem

#87

Post by namibj »

IncreasePosts wrote: post #86
theoreticalmal wrote: post #85

Earlier quoted context omitted.

I just scrapped an ICE mower for a battery powered one. No more winterizing, changing oil, or worrying about filling with gas. I still don’t like mowing, but it sucks a little less now

Sure, but you're just deferring moderate yearly maintenance cost for a rig that will need to be totally overhauled in 5 years due to battery degradation with current battery tech offered in mowers At least, that's the conclusion I came to this year when researching ride-on battery mowers vs ICE. Electric push mowers seem like a no brainer though

LiFePO4 will be even cheaper in 5 years, so go for it and have a project for then?

Re: The Ski Rental Problem

#88

Post by borroka »

svat wrote: post #44
eterm wrote: post #19

Earlier quoted context omitted.

It's known to wikipedia as the "Secretary Problem": https://en.wikipedia.org/wiki/Secretary_problem The optimum is actually based on 1/e rather than 1/3 but 1/3 is a good enough practical approximation.

In the secretary problem, you're trying to maximize the probability of selecting the absolutely best candidate. In other words you assume that you “win” if you select the best candidate and “lose” otherwise (even if you end up picking the second best who is almost as good!), and you're trying to maximize the probability of winning. (The optimal solution says you can win with probability 1/e ≈ 37%, meaning that ≈63% o…

It also assumes that the sequence is random and that there is no a priori information about the quality of the candidates.

A similar problem occurs in dating today, when people tend to dismiss the current option in the hope or expectation of finding someone better later, intuitively treating it as a secretary problem. But too many people fail to take full advantage of the knowledge they have of themselves and the type of partner they can attract, of the dating market and of the world in general, and end up bitter and disappointed and victims of their own poor choices.

Re: The Ski Rental Problem

#89

Post by trillic »

lisbbb wrote: post #13

Oh man, I had no idea that the decision of whether to rent or buy skis required calculus to solve. I just figured that if you ski more than say, 3 times a season, it's probably better to own your own gear for reasons unrelated to the entry cost, but more to do with comfort, tuning, quality, and so on. Anyone who has rented skis knows that the rental fleets are trashed.

This doesn't include the "Checked Bag fee" variable. Which is a significant component if you live somewhere you have to fly to ski.

Re: The Ski Rental Problem

#90

Post by porridgeraisin »

JohnKemeny wrote: post #29

Here's a different version of the problem. It takes 10 minutes to walk home from the bus central. The bus is late but should be here any minute now. The bus takes one minute. Do you wait or walk?

Don't you need to know the inter arrival time to solve this? I think the point is that it's a memory less distribution so you're expected to wait for the same time regardless of how long you've already waited.
Post reply on HN