• Log InLog In
  • Register
Liquid`
Team Liquid Liquipedia
EST 00:34
CET 06:34
KST 14:34
  • Home
  • Forum
  • Calendar
  • Streams
  • Liquipedia
  • Features
  • Store
  • EPT
  • TL+
  • StarCraft 2
  • Brood War
  • Smash
  • Heroes
  • Counter-Strike
  • Overwatch
  • Liquibet
  • Fantasy StarCraft
  • TLPD
  • StarCraft 2
  • Brood War
  • Blogs
Forum Sidebar
Events/Features
News
Featured News
Rongyi Cup S3 - RO16 Preview3herO wins SC2 All-Star Invitational10SC2 All-Star Invitational: Tournament Preview5RSL Revival - 2025 Season Finals Preview8RSL Season 3 - Playoffs Preview0
Community News
Weekly Cups (Jan 12-18): herO, MaxPax, Solar win0BSL Season 2025 - Full Overview and Conclusion8Weekly Cups (Jan 5-11): Clem wins big offline, Trigger upsets4$21,000 Rongyi Cup Season 3 announced (Jan 22-Feb 7)19Weekly Cups (Dec 29-Jan 4): Protoss rolls, 2v2 returns7
StarCraft 2
General
Oliveira Would Have Returned If EWC Continued StarCraft 2 not at the Esports World Cup 2026 Stellar Fest "01" Jersey Charity Auction PhD study /w SC2 - help with a survey! Rongyi Cup S3 - RO16 Preview
Tourneys
Arc Raiders Cat Bed Map Guide OSC Season 13 World Championship $21,000 Rongyi Cup Season 3 announced (Jan 22-Feb 7) $70 Prize Pool Ladder Legends Academy Weekly Open! SC2 All-Star Invitational: Jan 17-18
Strategy
Simple Questions Simple Answers
Custom Maps
[A] Starcraft Sound Mod
External Content
Mutation # 509 Doomsday Report Mutation # 508 Violent Night Mutation # 507 Well Trained Mutation # 506 Warp Zone
Brood War
General
Gypsy to Korea [ASL21] Potential Map Candidates Which foreign pros are considered the best? BW General Discussion BW AKA finder tool
Tourneys
Azhi's Colosseum - Season 2 [Megathread] Daily Proleagues Small VOD Thread 2.0 [BSL21] Non-Korean Championship - Starts Jan 10
Strategy
Current Meta Simple Questions, Simple Answers Soma's 9 hatch build from ASL Game 2 Game Theory for Starcraft
Other Games
General Games
Nintendo Switch Thread Battle Aces/David Kim RTS Megathread Stormgate/Frost Giant Megathread Beyond All Reason Awesome Games Done Quick 2026!
Dota 2
Official 'what is Dota anymore' discussion
League of Legends
Heroes of the Storm
Simple Questions, Simple Answers Heroes of the Storm 2.0
Hearthstone
Deck construction bug Heroes of StarCraft mini-set
TL Mafia
Vanilla Mini Mafia Mafia Game Mode Feedback/Ideas
Community
General
US Politics Mega-thread NASA and the Private Sector Canadian Politics Mega-thread Russo-Ukrainian War Thread Things Aren’t Peaceful in Palestine
Fan Clubs
The herO Fan Club! The IdrA Fan Club
Media & Entertainment
Anime Discussion Thread [Manga] One Piece
Sports
2024 - 2026 Football Thread
World Cup 2022
Tech Support
Computer Build, Upgrade & Buying Resource Thread
TL Community
The Automated Ban List
Blogs
Navigating the Risks and Rew…
TrAiDoS
My 2025 Magic: The Gathering…
DARKING
Life Update and thoughts.
FuDDx
How do archons sleep?
8882
James Bond movies ranking - pa…
Topin
Customize Sidebar...

Website Feedback

Closed Threads



Active: 1311 users

[Math Puzzle] Day5

Blogs > evanthebouncy!
Post a Reply
Normal
evanthebouncy!
Profile Blog Joined June 2006
United States12796 Posts
Last Edited: 2009-05-01 06:30:27
May 01 2009 06:27 GMT
#1
So another day!
Yesterday's puzzle was solved by raiame and datscilly, as they literally posted within 1 minutes of each other. Good job!

+ Show Spoiler [solution] +

Number each color 0 to n-1. Give each prisoner a pre-determined number-sum modded n. So each prisoner would have a mod-sum ranging from 0 to n-1. When a prisoner sees all other guy's hat, he adds all other guy's hats color together, and mod it with n. He then takes that out of his pre-determined sum, and say that the difference is his own hat.
This works because as long as the prisoner can guess the total sum correctly, subtracting the other guy's hat sum will give his own hat color.
The total number of sums possible mod_n is n numbers, and since each prisoner guess a pre-determined sum from 0 to n-1, one will match the total sum and therefore one would have the right answer for his own hat color.


Day5's puzzle:

I'll give something simple today...
A vendor sells toys, he buys the toys for $18 and sells them for $21. One day, a kid walks in and hands him $100 bill, since he does not have change, he walks to his neighbor, and breaks up the $100 bill(i.e. he gives neighbor the $100 bill, and his neighbor gives him $100 worth of smaller bills).
He then proceed to give the kid his toy and change for the purchase.
Soon his neighbor was back, "Your 100$ bill was fake!", The neighbor said, and demanded his $100 back. So the vendor gives $100 to his neighbor.

How much money did the vendor lose as a result of this transaction?

Extra:
Again, put answer in spoilers, clarification will be given(unlikely for this puzzle).

Difficulty Poll:
This is something I'd like to try for fun, just try to vote honest.
[image loading]

Poll: How difficult is this puzzle?
(Vote): Can't do it
(Vote): Think I have it
(Vote): Sure I did it right



Life is run, it is dance, it is fast, passionate and BAM!, you dance and sing and booze while you can for now is the time and time is mine. Smile and laugh when still can for now is the time and soon you die!
SpiritoftheTunA
Profile Blog Joined August 2006
United States20903 Posts
Last Edited: 2009-05-01 06:35:37
May 01 2009 06:32 GMT
#2
+ Show Spoiler +
assuming buying the toy for 18 dollars isn't counted in the transaction, 79 for change to the boy and 100 paid to the neighbor afterward, the kid never actually paid anything, so 179? if buying the toy is counted, then 197?

edit oh wait shit rofl the neighbor gave him a legit 100 so subtract 100 of lost money, 79 (not counting originally purchasing toy)/97 (counting it)?
posting on liquid sites in current year
EsX_Raptor
Profile Blog Joined February 2008
United States2802 Posts
May 01 2009 06:32 GMT
#3
+ Show Spoiler +
$118
SpiritoftheTunA
Profile Blog Joined August 2006
United States20903 Posts
May 01 2009 06:33 GMT
#4
On May 01 2009 15:32 EsX_Raptor wrote:
+ Show Spoiler +
$118

awesome
posting on liquid sites in current year
Ichigo1234551
Profile Blog Joined October 2008
United States649 Posts
Last Edited: 2009-05-01 06:39:19
May 01 2009 06:33 GMT
#5
+ Show Spoiler +

100 dollars because he gave the money back to his neighbor
I WILL DESTROY YOU IN 2009 OK???????????????
deathgod6
Profile Blog Joined January 2008
United States5064 Posts
Last Edited: 2009-05-01 06:42:34
May 01 2009 06:34 GMT
#6
Editting answer.
+ Show Spoiler +
Forgot the kid's bill was fake and misunderstood the question . The profit from the neighbor is $21, excluding the change he gives to the boy. The shopkeeper then has to give $100 back to the neighbor. He also lost the toy, so it would be -18+21-100, which would be $97 lost.
4.0 GPA = A rank 5.0 GPA = Olympic --------- Bisu, Best, Fantasy. i ♥ oov. They can get in my BoxeR anyday.
SpiritoftheTunA
Profile Blog Joined August 2006
United States20903 Posts
May 01 2009 06:37 GMT
#7
On May 01 2009 15:33 Ichigo1234551 wrote:
+ Show Spoiler +
100 dollars because he gave the money back to his neighbor

+ Show Spoiler +
full explanation please? o.O are you counting the fact that the change for the kid was 79?
posting on liquid sites in current year
Ota Solgryn
Profile Blog Joined January 2008
Denmark2011 Posts
May 01 2009 06:39 GMT
#8
+ Show Spoiler +
179$
ihasaKAROT: "Wish people would stop wasting their lives on finding flaws in others"
Ichigo1234551
Profile Blog Joined October 2008
United States649 Posts
May 01 2009 06:40 GMT
#9
On May 01 2009 15:37 SpiritoftheTunA wrote:
Show nested quote +
On May 01 2009 15:33 Ichigo1234551 wrote:
+ Show Spoiler +
100 dollars because he gave the money back to his neighbor

+ Show Spoiler +
full explanation please? o.O are you counting the fact that the change for the kid was 79?


+ Show Spoiler +
Its a trick question yo. He only asks us about the transaction that he gave the money back to his neighbor.
I WILL DESTROY YOU IN 2009 OK???????????????
SpiritoftheTunA
Profile Blog Joined August 2006
United States20903 Posts
May 01 2009 06:42 GMT
#10
On May 01 2009 15:40 Ichigo1234551 wrote:
Show nested quote +
On May 01 2009 15:37 SpiritoftheTunA wrote:
On May 01 2009 15:33 Ichigo1234551 wrote:
+ Show Spoiler +
100 dollars because he gave the money back to his neighbor

+ Show Spoiler +
full explanation please? o.O are you counting the fact that the change for the kid was 79?


+ Show Spoiler +
Its a trick question yo. He only asks us about the transaction that he gave the money back to his neighbor.

+ Show Spoiler +
no i think you're just picking the wrong antecedent for "this transaction"
posting on liquid sites in current year
Plutonium
Profile Joined November 2007
United States2217 Posts
Last Edited: 2009-05-01 06:49:17
May 01 2009 06:42 GMT
#11
nvm
delanZia
Profile Blog Joined October 2008
Australia34 Posts
Last Edited: 2009-05-01 06:44:14
May 01 2009 06:42 GMT
#12
+ Show Spoiler +
197, spent $18 on the toy, gave the kid $79 of real money as change and gave his neighbor $100 real money

edit
wait thats wrong haha
if not now then when?
Rhaegar99
Profile Blog Joined September 2008
Australia1190 Posts
May 01 2009 06:43 GMT
#13
+ Show Spoiler +
-18 for buying toy. +0 from fake money. +100 from neightbour. -79 from giving change. -100 from repaying neighbour. So lost $97 total.
deathgod6
Profile Blog Joined January 2008
United States5064 Posts
May 01 2009 06:44 GMT
#14
+ Show Spoiler +
Where is everyone getting $118? At least explain your answer guys? lol.
4.0 GPA = A rank 5.0 GPA = Olympic --------- Bisu, Best, Fantasy. i ♥ oov. They can get in my BoxeR anyday.
SpiritoftheTunA
Profile Blog Joined August 2006
United States20903 Posts
May 01 2009 06:45 GMT
#15
On May 01 2009 15:44 deathgod6 wrote:
+ Show Spoiler +
Where is everyone getting $118? At least explain your answer guys? lol.

seconded
posting on liquid sites in current year
Plutonium
Profile Joined November 2007
United States2217 Posts
Last Edited: 2009-05-01 06:49:01
May 01 2009 06:48 GMT
#16
Whoops, revised it.

+ Show Spoiler +
+21 selling to the kid
-18 for cost of toy
-100 for giving to neighbor

so he lost 97 dollars.
ktp
Profile Blog Joined January 2007
United States797 Posts
Last Edited: 2009-05-01 07:13:40
May 01 2009 07:07 GMT
#17
+ Show Spoiler +
He lost 97 dollars. His profit margin was $3. The transaction between the kid and his neighboor and stuff is all irrelevent. He still made 3 dollrs. Then the neighboor wanted 100 dollars back. So the earnings 3 minus 100 dollar is - 97. He lost 97 dollars.


and how did you guys voted in poll without before evan posted the correct answer is beyond me...
Malongo
Profile Blog Joined November 2005
Chile3472 Posts
May 01 2009 07:39 GMT
#18
+ Show Spoiler +
As ktp posted the transaction with the neighboor is irrelevent. Think that there was no neighbor and the vendor had the change. Boy comes in gives nothing picks change (-79) and leaves with the toy (-18). Total: lose 97 doll.
Help me! im still improving my English. An eye for an eye makes the whole world blind. M. G.
Ichigo1234551
Profile Blog Joined October 2008
United States649 Posts
May 01 2009 07:53 GMT
#19
-79 for the change he gave the kid back
-18 for the cost of the toy
-100 for the money he gave the vendor

so 197
I WILL DESTROY YOU IN 2009 OK???????????????
Malongo
Profile Blog Joined November 2005
Chile3472 Posts
May 01 2009 08:02 GMT
#20
Use spoilers+ Show Spoiler +

On May 01 2009 16:53 Ichigo1234551 wrote:
-79 for the change he gave the kid back
-18 for the cost of the toy
-100 for the money he gave the vendor

so 197

-197+ 100 from neighbor= -97
Help me! im still improving my English. An eye for an eye makes the whole world blind. M. G.
kOre
Profile Blog Joined April 2009
Canada3642 Posts
May 01 2009 10:01 GMT
#21
On May 01 2009 17:02 Malongo wrote:
Use spoilers+ Show Spoiler +

On May 01 2009 16:53 Ichigo1234551 wrote:
-79 for the change he gave the kid back
-18 for the cost of the toy
-100 for the money he gave the vendor

so 197

-197+ 100 from neighbor= -97

+ Show Spoiler +
You do know that the "+100 from neighbor" you have posted is the fake 100? So he actually does lose 197
http://www.starcraftmecca.net - Founder
Rhaegar99
Profile Blog Joined September 2008
Australia1190 Posts
May 01 2009 10:14 GMT
#22
On May 01 2009 19:01 kOre wrote:
Show nested quote +
On May 01 2009 17:02 Malongo wrote:
Use spoilers+ Show Spoiler +

On May 01 2009 16:53 Ichigo1234551 wrote:
-79 for the change he gave the kid back
-18 for the cost of the toy
-100 for the money he gave the vendor

so 197

-197+ 100 from neighbor= -97

+ Show Spoiler +
You do know that the "+100 from neighbor" you have posted is the fake 100? So he actually does lose 197


+ Show Spoiler +
The fake 100 is from the boy not the neighbours
kemoryan
Profile Blog Joined December 2007
Spain1506 Posts
Last Edited: 2009-05-01 11:43:31
May 01 2009 11:38 GMT
#23
+ Show Spoiler +

-18 -> cost of toy
+100 -> the money his neighbor gives
-79 -> change to the kid (real $).
-100 -> the money he gives back to neighbor
-----
-97
Freedom is a stranger
trickser
Profile Joined October 2006
Germany139 Posts
Last Edited: 2009-05-01 12:23:40
May 01 2009 12:21 GMT
#24
+ Show Spoiler +
-18 for purchasing the toy. Then he gives 79 back to the kid. Which leaves him with 21. Now he got to give back the 100$. So its 21-100-18= -97
Heart Catch Pre-Cure. Saa Mina De! Heart Catch Pre-Cure Hanasaka Seyo!
Scooter
Profile Blog Joined November 2007
United States747 Posts
May 01 2009 12:53 GMT
#25
+ Show Spoiler +
97 dollars, but I thought about it a little differently. Remember the kid gets smaller bills from the neighbor, so when he buys the toy ideally he gets no change back, but the point is he pays with real money. Vendor makes 3 dollars, but then has to lose 100 dollars to the neighbor.
My unblocks gets yo curleh mustache wet のωの
reachfortherings
Profile Joined January 2009
63 Posts
May 01 2009 13:22 GMT
#26
--- Nuked ---
Day[9]
Profile Blog Joined April 2003
United States7366 Posts
May 01 2009 13:53 GMT
#27
as a math major, i have to say that the question is painfully imprecisely worded
Whenever I encounter some little hitch, or some of my orbs get out of orbit, nothing pleases me so much as to make the crooked straight and crush down uneven places. www.day9.tv
fearus
Profile Blog Joined December 2003
China2164 Posts
May 01 2009 16:30 GMT
#28
+ Show Spoiler +

He lost $79 from the transaction.

Whether or not the kid ever walked into the shop is irrelevant to his original purchase of $18
bisu fanboy
inReacH
Profile Blog Joined August 2008
Sweden1612 Posts
May 01 2009 16:51 GMT
#29
On May 01 2009 22:53 Day[9] wrote:
as a math major, i have to say that the question is painfully imprecisely worded


I can't imagine this being hard to understand.
patrick321
Profile Joined August 2004
United States185 Posts
Last Edited: 2009-05-01 17:07:37
May 01 2009 17:05 GMT
#30
+ Show Spoiler +
start
lender vendor boy
(100) (100+toy) (100f)

end
lender vendor boy
(100) (21 + 100f) (79+toy)

It's a closed system so we can just look at the beginning and the end. The lender's money doesn't change so he's ignored. Since the boy gains 79 + toy the vendor must have lost 79 + toy which equates to 97. This makes since because all the vendor is really out is the fake hundred plus the difference in the toy's buy/sell price.

edit-made numbers easier to tell apart.
LxRogue
Profile Blog Joined March 2007
United States1415 Posts
May 01 2009 19:32 GMT
#31
+ Show Spoiler +
$3 profit
$100 loss
net $97 loss
rANDY
Profile Blog Joined November 2005
United Kingdom748 Posts
May 01 2009 20:41 GMT
#32
just read the op so far
we assume the child with $100 buys as many toys as he can with the $100, as all children would, or 1, which i assume is more likely intended.
Everywhere
Profile Blog Joined March 2009
United States97 Posts
May 01 2009 21:32 GMT
#33
+ Show Spoiler +

+$3
-$100
total = -$97
Macavenger
Profile Blog Joined January 2008
United States1132 Posts
May 01 2009 22:13 GMT
#34
On May 02 2009 01:51 inReacH wrote:
Show nested quote +
On May 01 2009 22:53 Day[9] wrote:
as a math major, i have to say that the question is painfully imprecisely worded


I can't imagine this being hard to understand.

Pretty sure you don't think about it like a math major.

+ Show Spoiler +
The tricky part is "this transaction," which as written could refer to any of the total net loss the toy plus the fake 100, the loss from just the trades with the neighbor, or the loss just from being forced to give 100 back to the neighbor. The math is trivial in all cases and the problem is unclear as to the definition of the transaction, so honestly this isn't a math problem at all, but more of a literature problem of "what did the author actually mean."

That said, to me the most natural interpretation of "transaction" here would be exchanging money with the boy and then having to give money back to the neighbor. The original cost of the toy was paid at a another time, a sunk cost, and wouldn't count for this. Thus, I would consider his loss for "this transaction" as $79. I'd say the people saying $97 have nearly as good an argument, though.
Normal
Please log in or register to reply.
Live Events Refresh
Next event in 5h 26m
[ Submit Event ]
Live Streams
Refresh
StarCraft 2
RuFF_SC2 228
SortOf 58
StarCraft: Brood War
Shuttle 62
ZergMaN 52
Shine 49
Hm[arnc] 34
Noble 33
Icarus 11
Dota 2
NeuroSwarm214
League of Legends
JimRising 814
C9.Mang0505
Counter-Strike
taco 472
Super Smash Bros
Mew2King216
Other Games
summit1g6953
KnowMe177
monkeys_forever119
Organizations
Other Games
gamesdonequick1258
StarCraft: Brood War
UltimateBattle 108
StarCraft 2
Blizzard YouTube
StarCraft: Brood War
BSLTrovo
sctven
[ Show 14 non-featured ]
StarCraft 2
• AfreecaTV YouTube
• intothetv
• Kozan
• IndyKCrew
• LaughNgamezSOOP
• Laughngamez YouTube
• Migwel
• sooper7s
StarCraft: Brood War
• RayReign 45
• BSLYoutube
• STPLYoutube
• ZZZeroYoutube
League of Legends
• Lourlo1122
• Stunt396
Upcoming Events
RongYI Cup
5h 26m
Clem vs ShoWTimE
Zoun vs Bunny
Big Brain Bouts
11h 26m
Percival vs Gerald
Serral vs MaxPax
RongYI Cup
1d 5h
SHIN vs Creator
Classic vs Percival
OSC
1d 7h
BSL 21
1d 9h
RongYI Cup
2 days
Maru vs Cyan
Solar vs Krystianer
uThermal 2v2 Circuit
2 days
BSL 21
2 days
Wardi Open
3 days
Monday Night Weeklies
3 days
[ Show More ]
OSC
3 days
WardiTV Invitational
4 days
WardiTV Invitational
5 days
The PondCast
6 days
Liquipedia Results

Completed

Proleague 2026-01-20
OSC Championship Season 13
NA Kuram Kup

Ongoing

C-Race Season 1
BSL 21 Non-Korean Championship
CSL 2025 WINTER (S19)
KCM Race Survival 2026 Season 1
Escore Tournament S1: W5
Rongyi Cup S3
Underdog Cup #3
BLAST Bounty Winter 2026
BLAST Bounty Winter Qual
eXTREMESLAND 2025
SL Budapest Major 2025
ESL Impact League Season 8
BLAST Rivals Fall 2025

Upcoming

Acropolis #4 - TS4
Acropolis #4
IPSL Spring 2026
uThermal 2v2 2026 Main Event
Bellum Gens Elite Stara Zagora 2026
HSC XXVIII
Nations Cup 2026
Tektek Cup #1
PGL Bucharest 2026
Stake Ranked Episode 1
BLAST Open Spring 2026
ESL Pro League Season 23
ESL Pro League Season 23
PGL Cluj-Napoca 2026
IEM Kraków 2026
TLPD

1. ByuN
2. TY
3. Dark
4. Solar
5. Stats
6. Nerchio
7. sOs
8. soO
9. INnoVation
10. Elazer
1. Rain
2. Flash
3. EffOrt
4. Last
5. Bisu
6. Soulkey
7. Mini
8. Sharp
Sidebar Settings...

Advertising | Privacy Policy | Terms Of Use | Contact Us

Original banner artwork: Jim Warren
The contents of this webpage are copyright © 2026 TLnet. All Rights Reserved.