AugustaAdaByron Posted December 11, 2015 Report Share Posted December 11, 2015 Very good! And that brings up the next question. I always use 3.1415927 for π. So I guess that means when I was in high school, we had 8-digit calculators. What does everybody else use? log(x)/log(2) OR ln(x)/ln(2) Yes, that works, too. I just decided to choose the highest power of 2 that is within the range. Integer number. Of course. I don't even remember. I think I had (still have somewhere at home) a CASIO. I always liked Texas Instruments though. No idea why. I like your attention to detail! Quote Level "I have no clue" Warrior Current challenge Battle log Link to comment
Artinum Posted December 12, 2015 Report Share Posted December 12, 2015 Since I didn't want to double post... Here's another math thing. One is more likely to win the grand prize for the lottery twice in a row buying only a single ticket (Megamillions) than he is to rebuild a solved rubix cube from the disassembled pieces. However, the odds of his rebuilt cube being solvable are 1/12 The way I'm interpreting that, you're suggesting that you would be more likely to win the lottery twice in a row with the same numbers than you would be to build a Rubix cube with all the pieces in the right places. I can only assume this is incorrect, as there are factories that assemble thousands of cubes a day without issue! I'm not familiar with the "Megamillions" draw - is it the same as the "choose six from 49" odds we have for the UK lottery? If so, you'd be looking at some pretty long odds (in the region of one in 196,000,000,000,000). Very good! And that brings up the next question. I always use 3.1415927 for π. So I guess that means when I was in high school, we had 8-digit calculators. What does everybody else use? If I'm working out rough estimates, I just use 3.14. I seldom need to use a more accurate version of pi. In algebraic terms, I just keep pi as a constant variable (unless I want to come up with some rough bounds, in which case 3.14 is again pretty okay). For angles, I prefer to think in degrees rather than radians. Computers seem to disagree. When I had a bash at coding an asteroids game, I created some lookup tables for angles (much faster than calculating them on the fly) and converted to degrees, because to hell with you, computer. Quote What happens when you play Final Fantasy VII with everyone called Cloud? It gets quite confusing... https://ff7crowdofclouds.wordpress.com/ Link to comment
goodbye_farewell Posted December 12, 2015 Report Share Posted December 12, 2015 The key is in the wording:She did not say "by." She said "on." Very clever. After all the explaining, this is the only bit I needed [emoji14] 1 Quote Link to comment
caeliter Posted December 12, 2015 Report Share Posted December 12, 2015 The way I'm interpreting that, you're suggesting that you would be more likely to win the lottery twice in a row with the same numbers than you would be to build a Rubix cube with all the pieces in the right places. I can only assume this is incorrect, as there are factories that assemble thousands of cubes a day without issue! I'm not familiar with the "Megamillions" draw - is it the same as the "choose six from 49" odds we have for the UK lottery? If so, you'd be looking at some pretty long odds (in the region of one in 196,000,000,000,000). I meant to say, "assemble it blindfolded" but forgot to write the word blindfolded (went back and edited) I was saying that, if I were to buy one megamillions ticket this week (odds are 1:258,890,850) and win, then buy another ticket next week (but only one ticket) and win again, that would be a more likely scenario (1:67,024,472,213,722,500) than a man correctly assembling a rubix cube without being able to see the pieces. (1:519,024,039,293,878,272,000) Megamillions is draw 5 numbers from a pool of 75 and then draw a separate number from a pool of 15. Must match all 6 to win the top prize. Quote Link to comment
Artinum Posted December 12, 2015 Report Share Posted December 12, 2015 Right, that makes more sense! Quote What happens when you play Final Fantasy VII with everyone called Cloud? It gets quite confusing... https://ff7crowdofclouds.wordpress.com/ Link to comment
Emerald_Dragonfly Posted December 13, 2015 Report Share Posted December 13, 2015 Ahhh, maths. How have I missed this thread? My real life super power is teaching Algebra I to 7th graders (loved every minute of the 7 years that I did it). :-)Not a legit mathematician, though. I just really like it! Quote ~Emerald_Dragonfly Level 13 Warrior Link to comment
Sam Ashen Posted December 14, 2015 Report Share Posted December 14, 2015 So are we going to start a Physics thread or are we going to dump problems over here because they are related? 1 Quote Classless Human Male Warrior - Introduction Height: 1.77m Weight: 93 kg Spoiler Current Maxes: (repsxkg) Squat: 10x122.3, 5x138.2, 3x147; 1x170 Bench Press: 10x79, 5x93, 1x102 Deadlift: 10x152, 5x192, 3x210, 1x229 Overhead Press: 10x52, 5x61, 1x70.3 Current Battle Log: 1707 Sam Ashen Summer Swole Program 2017 Challenges: 1701 1702 1703 1704 1705 Previous Challenges: 1 2 3 4 5 6 7 8 1603 1604 1605 1606 1607 1609 1610 1611 1612 Daily Log:The Daily Grind Form Check: Stronglifts Olympic More FC's: Pistol Squats Want to play? MFPvP Link to comment
goodbye_farewell Posted December 14, 2015 Report Share Posted December 14, 2015 So are we going to start a Physics thread or are we going to dump problems over here because they are related?Haha I was wondering the same thing... Quote Link to comment
GoldLynx Posted December 14, 2015 Author Report Share Posted December 14, 2015 So are we going to start a Physics thread or are we going to dump problems over here because they are related? I thought it would work fine to combine them into one thread, but there seems to be division in the troops. Feel free to start a physics thread. Quote We do not show off, for we are the unseen. We are not motivated by aesthetics, but effectiveness. Our bodies are our weapons, not our trophies.They are the civilians.We are the warriors. Link to comment
Estrix Posted December 14, 2015 Report Share Posted December 14, 2015 Seems fairly likely to me that it will be more or less the same individuals with an interest in both threads so they may as well be together. Although I suppose some people like the neat division of a thread each. Quote The valiant never taste of death but once. Battle Log: 100 Day Bench Press Challenge (64 Days) Challenge: 1, 2 Estrix, level 1 Goblin Raider STR 3|DEX 2|STA 3|CON 3|WIS 3|CHA 2 Link to comment
Mark D Posted December 14, 2015 Report Share Posted December 14, 2015 If a chicken-and-a-half lays an egg-and-a-half in a day-and-a-half, how many eggs will one chicken lay in one day? Quote My character: https://www.nerdfitness.com/character/58572/ Current Challenge:http://rebellion.nerdfitness.com/index.php?/topic/83683-mark-d-walks-up-to-a-barbell/ Previous Challenges: 9 8 7 6 5 4 3 2 1 Link to comment
Sam Ashen Posted December 14, 2015 Report Share Posted December 14, 2015 Is that related to: The north side of a roof is sloped at 30 degrees and the south side of the same roof is sloped at 40 degrees. If a rooster lays an egg at the top of the roof, which direction is it most likely to roll? Quote Classless Human Male Warrior - Introduction Height: 1.77m Weight: 93 kg Spoiler Current Maxes: (repsxkg) Squat: 10x122.3, 5x138.2, 3x147; 1x170 Bench Press: 10x79, 5x93, 1x102 Deadlift: 10x152, 5x192, 3x210, 1x229 Overhead Press: 10x52, 5x61, 1x70.3 Current Battle Log: 1707 Sam Ashen Summer Swole Program 2017 Challenges: 1701 1702 1703 1704 1705 Previous Challenges: 1 2 3 4 5 6 7 8 1603 1604 1605 1606 1607 1609 1610 1611 1612 Daily Log:The Daily Grind Form Check: Stronglifts Olympic More FC's: Pistol Squats Want to play? MFPvP Link to comment
AugustaAdaByron Posted December 14, 2015 Report Share Posted December 14, 2015 The answer to both is 42! (that's not factorial) Quote Level "I have no clue" Warrior Current challenge Battle log Link to comment
Oramac Posted December 14, 2015 Report Share Posted December 14, 2015 OK Guys help me out here. This ought to be a cakewalk for you. Say I have a product and I'm going to retail it. My cost is $100. I was taught that a 30% markup would be (cost*1.3) = $130. I just got off the phone with a lady who told me that's wrong, and it should be (cost/.7) = $142.86. The second version doesn't make any damn sense to me. Quote "Someone ever tries to kill you, you try to kill 'em right back." - Captain Malcolm Reynolds Current Challenge Also, I Agree With Tank™ Link to comment
Mark D Posted December 14, 2015 Report Share Posted December 14, 2015 Is that related to: The north side of a roof is sloped at 30 degrees and the south side of the same roof is sloped at 40 degrees. If a rooster lays an egg at the top of the roof, which direction is it most likely to roll? Nope, there actually IS a numeric answer, and it's not 1. OK Guys help me out here. This ought to be a cakewalk for you. Say I have a product and I'm going to retail it. My cost is $100. I was taught that a 30% markup would be (cost*1.3) = $130. I just got off the phone with a lady who told me that's wrong, and it should be (cost/.7) = $142.86. The second version doesn't make any damn sense to me. You're calculating price as 30% higher than cost. She's calculating cost as 70% of final price (obviously that makes final price = cost+42.86%). Sounds like she does a lot of government contracts....... "The first rule of government contracts is you never build one when you can build two for twice the price". - From the movie Contact. 2 Quote My character: https://www.nerdfitness.com/character/58572/ Current Challenge:http://rebellion.nerdfitness.com/index.php?/topic/83683-mark-d-walks-up-to-a-barbell/ Previous Challenges: 9 8 7 6 5 4 3 2 1 Link to comment
Sam Ashen Posted December 14, 2015 Report Share Posted December 14, 2015 Hmm. I am looking at....2615 Volts Line to Ground32.31 Amps7300 Watts(per phase) What's wrong with imaginary numbers? 14500 Volts Line to Ground190 Amps68000 Watts per Phase, 3 Phases at the difference a 0.32 degree phase angle shift. ^^This is exactly how I was feeling about trying to express electrical loss in horsepower. Quote Classless Human Male Warrior - Introduction Height: 1.77m Weight: 93 kg Spoiler Current Maxes: (repsxkg) Squat: 10x122.3, 5x138.2, 3x147; 1x170 Bench Press: 10x79, 5x93, 1x102 Deadlift: 10x152, 5x192, 3x210, 1x229 Overhead Press: 10x52, 5x61, 1x70.3 Current Battle Log: 1707 Sam Ashen Summer Swole Program 2017 Challenges: 1701 1702 1703 1704 1705 Previous Challenges: 1 2 3 4 5 6 7 8 1603 1604 1605 1606 1607 1609 1610 1611 1612 Daily Log:The Daily Grind Form Check: Stronglifts Olympic More FC's: Pistol Squats Want to play? MFPvP Link to comment
Oramac Posted December 14, 2015 Report Share Posted December 14, 2015 ^^This is exactly how I was feeling about trying to express electrical loss in horsepower. Meh. I don't like cats. Quote "Someone ever tries to kill you, you try to kill 'em right back." - Captain Malcolm Reynolds Current Challenge Also, I Agree With Tank™ Link to comment
caeliter Posted December 14, 2015 Report Share Posted December 14, 2015 Nope, there actually IS a numeric answer, and it's not 1. Can a chicken lay 2/3 of an egg? (Did I do it wrong?) Quote Link to comment
Mark D Posted December 14, 2015 Report Share Posted December 14, 2015 Can a chicken lay 2/3 of an egg? (Did I do it wrong?)Nope exactly right.Question two:If a chicken and a half lays an egg and a half in a day and a half, how long will it take a centipede with one wooden leg to kick the seeds out of a dill pickle?Answer: blue, because aliens don't surf.Here endeth the lesson. 2 Quote My character: https://www.nerdfitness.com/character/58572/ Current Challenge:http://rebellion.nerdfitness.com/index.php?/topic/83683-mark-d-walks-up-to-a-barbell/ Previous Challenges: 9 8 7 6 5 4 3 2 1 Link to comment
Sam Ashen Posted December 16, 2015 Report Share Posted December 16, 2015 Facebook newb here. I think I am at 90 friends now. What is the probability none of them share a birthday? 1 Quote Classless Human Male Warrior - Introduction Height: 1.77m Weight: 93 kg Spoiler Current Maxes: (repsxkg) Squat: 10x122.3, 5x138.2, 3x147; 1x170 Bench Press: 10x79, 5x93, 1x102 Deadlift: 10x152, 5x192, 3x210, 1x229 Overhead Press: 10x52, 5x61, 1x70.3 Current Battle Log: 1707 Sam Ashen Summer Swole Program 2017 Challenges: 1701 1702 1703 1704 1705 Previous Challenges: 1 2 3 4 5 6 7 8 1603 1604 1605 1606 1607 1609 1610 1611 1612 Daily Log:The Daily Grind Form Check: Stronglifts Olympic More FC's: Pistol Squats Want to play? MFPvP Link to comment
GoldLynx Posted December 16, 2015 Author Report Share Posted December 16, 2015 If a chicken-and-a-half lays an egg-and-a-half in a day-and-a-half, how many eggs will one chicken lay in one day? This means that three chickens (twice the number) will lay three eggs in those one and a half days. In three days, therefore, three chickens will lay six eggs. So in three days, one chicken will lay a third that number, or two eggs. Two eggs in three days =2/3 egg/day*chicken. 2 Quote We do not show off, for we are the unseen. We are not motivated by aesthetics, but effectiveness. Our bodies are our weapons, not our trophies.They are the civilians.We are the warriors. Link to comment
AugustaAdaByron Posted December 16, 2015 Report Share Posted December 16, 2015 Facebook newb here. I think I am at 90 friends now. What is the probability none of them share a birthday? Very very small. Less than 0.1%. (Assuming we're just thinking of day and month and not year.) To make it easier to describe let's assume that none of them was born on the 29th of February and that they could have been born on any day of each year with equal probability. Consider any arbitrary list of your friends. Your first friend could have been born on any day of the year. Thus, 365 possible days.Your second friend will have to have been born on a different day of the year than the first one. Thus, 364 possible days.The third friend will have to have been born on different days than the previous two. Thus, 363 possible days....Your 90th friend will have to have been born on a different day of the year than the previous 89. Thus, 276 possible days. However, since each one of them could have been born on any day with equal probability. We get 365^{90} different events that could have occurred, each one of them with equal probability.This means that the probability that non of them share birthday is, (365 x 364 x 363 x ... x 276)/365^{90}. Nice problem! btw, I have 3 Facebook friends who have birthday today. P.S.: It's very possible that I've made some mistake on the calculations. Some + or - 1, for example. (But you get the idea.) P.S2: When you reach 366-367 friends then the probability will be 0 and it will be certain that two of them share birthday. 3 Quote Level "I have no clue" Warrior Current challenge Battle log Link to comment
Sam Ashen Posted December 16, 2015 Report Share Posted December 16, 2015 Very very small. Less than 0.1%. (Assuming we're just thinking of day and month and not year.) To make it easier to describe let's assume that none of them was born on the 29th of February and that they could have been born on any day of each year with equal probability. Consider any arbitrary list of your friends. Your first friend could have been born on any day of the year. Thus, 365 possible days.Your second friend will have to have been born on a different day of the year than the first one. Thus, 364 possible days.The third friend will have to have been born on different days than the previous two. Thus, 363 possible days....Your 90th friend will have to have been born on a different day of the year than the previous 89. Thus, 276 possible days. However, since each one of them could have been born on any day with equal probability. We get 365^{90} different events that could have occurred, each one of them with equal probability.This means that the probability that non of them share birthday is, (365 x 364 x 363 x ... x 276)/365^{90}. Well done! I get something like 1 in 162,500 or so. At about 22 or 23 or so it is about even, if I remember correctly. Once you hit 30 or so you have a very good bet. Now if I want to consider the number 22, I might approximate as follows: P = (354/365)²² = 51% probability of 22 unique birthdays. Putting it into Excel I get 52.4%. The difference is in one of the assumptions I named. Number 23 puts us less than even. Nice problem! Thanks! Quote Classless Human Male Warrior - Introduction Height: 1.77m Weight: 93 kg Spoiler Current Maxes: (repsxkg) Squat: 10x122.3, 5x138.2, 3x147; 1x170 Bench Press: 10x79, 5x93, 1x102 Deadlift: 10x152, 5x192, 3x210, 1x229 Overhead Press: 10x52, 5x61, 1x70.3 Current Battle Log: 1707 Sam Ashen Summer Swole Program 2017 Challenges: 1701 1702 1703 1704 1705 Previous Challenges: 1 2 3 4 5 6 7 8 1603 1604 1605 1606 1607 1609 1610 1611 1612 Daily Log:The Daily Grind Form Check: Stronglifts Olympic More FC's: Pistol Squats Want to play? MFPvP Link to comment
AugustaAdaByron Posted December 16, 2015 Report Share Posted December 16, 2015 Yup! Around 23 it is even. I'm too lazy to actually do the calculations though. After 100 it's practically certain. Quote Level "I have no clue" Warrior Current challenge Battle log Link to comment
AugustaAdaByron Posted December 16, 2015 Report Share Posted December 16, 2015 OK, that's a bit more logic-based than just mathematics and it's fairly well-known but let me say it. Let us assume that there is an island where of all the inhabitants there are exactly k of them with blue eyes. No one however knows the colour of their eyes, no one can tell them and they have no reflective surfaces to see the colour of their eyes (no, not even the water). They can only see the colour of the eyes of all other inhabitants. The population is not very big and thus they all meet together early every night. However, for some completely crazy and random law whoever has blue eyes has to leave the island at midnight. One day a new person visits and right after midnight makes the comment "At least one of you has blue eyes". The person is honest so they're telling the truth. The inhabitants are all reasonable and law-abiding so as soon as someone finds out that they have blue eyes they leave the island at midnight. What's going to happen after they learn that at least one person has blue eyes? Quote Level "I have no clue" Warrior Current challenge Battle log Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.