Riddle Definition and 148 Threads

There are 9 jars of jellybeans, 8 of these jars contain jelly beans with a mass 1 gram, one jar contains j beans with masses of 1.1 grams. The only tool available to you is an electronic gram measure, which melts after giving you one measurement. How do you find the jar with the jelly beans of...

Got a riddle similar to this week's High School POTW; not sure where to post it, so I'll post it here: John was born in 1987, and is now (2012) 12 years old. How can that be?

Bobby and Cindy are in different math classes. Bobby got a 75 on his test and Cindy got a 70 (surprisingly low for children of an architect). Bobby’s class had a mean of 80 and a standard deviation of 5. Cindy’s class had a mean of 75 and a standard deviation of 10. Who did better on their test...

It's, supposedly, never been solved, but I believe I've solved it. My solution has been PM'd to a moderator, so there's no question of cheating on my part. Here's the riddle in the original: Ic waes faemne geong, feaxhar cwene ond aenlic rinc on ane tid; fleah mid...

Homework Statement Through a combination of sight, sound, and smell a rabbit can detect a fox at 60 meters. When the rabbit detects the fox, it runs immediately straight to its hole. If the fox can run twice as fast as the rabbit, what is the maximum distance from its hole that a rabbit can...

You're in a space station. It's shaped like inner tube of a tire. It's rotating, you're standing on the floor inside "inner tube" station. (the floor is the inside part of outer rim of tube) You are holding a marble, you are standing sideways with respect to rotation. (the space station is...

1. Homework Statement 1)If I stop moving you are going to be bored.No video games ,no facebook,no fan,no light nothing. 2)I f i start moving i am named after my master ,a very great talented man. 3)I have mass and occupy space. 4)If (3)can be written as nzggvi what is ksbhssrxh. 5)If one...

Given 1000 cows and 10 pens, you want to arrange the cows in the pens such that any number of cows from 1 to 1000 can be obtained by opening certain pens and taking all the cows in those pens. How do you arrange the cows in the pens?

This puzzle is about a square-headed architect who is designing a museum in the shape of an nxnxh square box, where n is an integer denoting the side length and h is the height of the building. Building design is subject to the following additional constraints: 1. For any n chosen there will...

Frank and Sammy bought a watermelon for forty-eight cents, Frank contributing thirty cents and Sammy eighteen, which they were going to divide in proportion to their relative investements, when, spying Billy passing on the road, they conspired to unload a third of the melon upon him for the cost...

Equation written on a car--Is it a riddle? I hope this is the right place to post this question. I saw this equation on a car's back windshield. I don't know what it means, but I'm really curious why someone would put it on their car. Is it a riddle of some kind? A famous equation...

Hard Riddle i guess! This is a tough one for me and i can't guess what is really the answer. Maybe one intellegent person here could do so. I am found on every playground. I am found in every office building I am long... but also short I am fat but sometimes skinny I make dogs bark...

Five pirates are trying to split up 1000 gold pieces. The rules are as follows: Pirate #5 must divide the gold up in such a way that a majority of the pirates (including himself) agree to. If he does not get a majority vote, he will be killed, and pirate #4 will get to propose a solution to the...

so you have room, and in said room you have three people...one always tells the truth, one always lies, and one sometimes tells the truth and sometimes lies. you can ask three questions, to any of the individuals, but no more than three. IE, if you ask one person three questions, you have no...

remove wrong forum/problem solved though thanks

riddle question " max profit + units " Homework Statement There is no demand for a new brand of mobile phones if the price is 20 $ or more. For each drop of 1 $ in the price, the demand increases by 500 units.The cost of producing x units is (12x + 2000)$. How many phones should be produced...

I'm on the search for graduate schools, most likely in Aerospace Engineering (coming from a B.S. in Physics). I'm considering some of the Embry Riddle Worldwide campuses, particularly the Kanehoe campus in Hawaii. The cost is much cheaper compared to the main campuses and being in Hawaii sounds...

hello .. Homework Statement A company will manufacture a total of 5000 units of its product at plants A and B. At plan A the unit cost for labor and material combined is 2.50 $, while at plant B it is 3.00 $. The fixed costs at plant A are 6000 $ and at plant B they are 8000 $. Between...

Homework Statement Best Rentals charges a daily fee plus a mileage fee for renting its cars. Jack was charged 40 $ for 500 kilometers, while Kelly was charged 70 $ for 1000 kilometers. What does Best Rental charge per day and per kilometer? The Attempt at a Solution I want to confirm...

hi all ,,,, Homework Statement Four years ago, kelly was twice as old as her brother. Find the present age of kelly and her brother if the product of their ages today is 160. The Attempt at a Solution well,, I tried with this method 2x+x=152 ,,,,, => ( 2x+4 ) + (x+4) = 160...

What has a mouth but cannot talk, what can run but never walks? what has a head but cannot weep. what has a bed but cannot sleep?

A factory has built a robot which moves on all squares of a 6*6 table. There is an arrow On all of the squares of the table when it moves on an square it reads the arrow the square and moves according to the square but before doing that it changes the arrow of the square aim to the previous...

This is a cool riddle of logic that I heard recently. It is supposed to be drawn out so I'll try to describe it as best as I can. Four prisoners of war are sentenced to death by firing squad. They line them up from north to south, all of them facing north (so that they are in line facing...

an emperor judged three prisoners to be executed, but he gave an exception to whomever gives the correct answer to his riddle will be set free. first, he asked them to line up, in a way where the first can’t see the two behind him, the second can see the one on front of him, and the third can...

Hi all If don't know if there's a thread about this one but I just simply couldn't go back and read every single thread so here we are: • There are 5 houses in 5 different colors • In each house lives a person with a different nationality • These 5 owners drink a certain type of...

I heard this riddle on the radio today, but then missed the solution. Caveat: I cannot remember the exact wording. Here are two possible variations: You will touch this 25 times before you will buy it. This will be touched 25 times before you buy it. Now I'm dying to know.

Assume you have 27 cards numbered 1-27. You and your partner have do devise some strategy so that for any 4 cards that you pick (without your partner seeing) you'll be able to tell him what they are by showing him only three of them. The only way that you can use the three cards that you show...

What moves without feet in the morning, travels on four feet in the afternoon, and walks on two feet at night? Answer: Man - in evolution from swimming organism to quadrupedal animals to bipedal people.[/color]

Hey, guys ! I have to calculate: \sum 1/(2n + 1)^2 n from 0 to infinite Knowing that 1/n² = (pi)²/6 The answer is (pi)²/8 I don't know why I'm stuck here but I just don't get it... Greetings

Last night my friends and I had a discussion about a science riddle that one of them had brought up. The question triggered some debate and the four of us were split in half with our answers. The question/riddle is: If you're standing on top of a train traveling at 50mph and you throw a...

Homework Statement The inductive hypothesis P(n): For any counting number n in N, and set of billiard balls with n members, all the balls have the same color. Pf) Consider any set A of n+1 balls, and the subsets B=(first n balls), C=(last n balls) The inductive hypothesis applies to both B...

"from strong came sweet" how is that possible?

Recently (25 July) Lee Smolin posted an update of his December 2007 unification paper http://arxiv.org/abs/0712.0977 The Plebanski action extended to a unification of gravity and Yang-Mills theory "We study a unification of gravity with Yang-Mills fields based on a simple extension of the...

All but two of my cars are Fords, all but two of my cars are Toyotas and all but two of my cars are Hondas. How many cars do I have. The obvious answer is three. I'm arguing with some folks that are claiming two is an acceptable answer and they are using the rationale that it is fine to...

I read a remarkable article in the newspaper a few days ago, I was wondering if anyone has ever experienced such a thing? It is at least something to pay attention to. Link: http://www.nrc.nl/achtergrond/article1157911.ece/Het_pijnboomraadsel Apparently quite a few people experience an...

I wanted to put it into brain teasers, but forum didn't allow me to use images there - they were converted to links. Can you hear it?

The difference between two positive numbers is 3. The difference between their reciprocals is 1/90 What are the two numbers? I worked out that: x-y=3 and 1/x-1/y= 1/90 Is that right so far?

Let me come back with a totally different ant riddle :smile: I hope this one has not been posted already. As far as I know, it should be attributed originally to Martin Gardner. This time, let us put a (point-like) ant on the edge (mathematically idealized) one meter long elastic band. The...

"Yes it's true, but why...?" A calculus riddle (of sorts) involving definitions Homework Statement Here's the story: I'm in an AP B/C Calculus class and our current activity is "engaging in an all out study frenzy before the AP exam." We've already gone over all of the material in the book...

If you have 500 questions (put right or wrong questions) and you will solve them all randomly as you don't know the answer so what is your probability to solve them all right? express answer as e.g 1.5*10^-2 ( don't think to try combinations one by one) You can easily solve that 2 right...

Solve my simple riddle! If you have 500 questions (put right or wrong questions) and you will solve them all randomly as you don't know the answer so what is your probability to solve them all right? express answer as e.g 1.5*10^-2

I am hot but I need fire, I am tall but I need to jump, I am long but I need to stretch and I am slimy but I need slime, I am full but I need fuel. I end in X. What am I?

Know the answer ? It is from this competition: http://www.tricksandriddles.com/html/riddle_competition.html" I begin with T, end in T and have T within. What am I ? Thanks.

Bought these two glass bulbs at a local art fair, the other month Size and shape as in Christmass tree balls, of hand blown glass but with a complex delicate glass object inside. Looks like ship in a bottle, but how do you get an object like that inside during the glass blowing...

My dad gave me this riddle eight months ago, can anyone help? Why doesn't a bicycle fall over when its moving. P.S its not balance , as you can push it and it won't fall over for a while.

I'm reading "Surely you're joking, Mr. Feynman!" which is one of the funniest and interesting books I've ever read! However, in one paragraph, Feynman is talking with some topology students about a riddle: The topology students: "You've got an orange, OK? Now you cut the orange into a...

OK, I'm sure you clever guys can sort this for me. I'm sure you've all seen this. I can't understand it at all and it's driving me nuts! Help! They both look the same and I have even measured them! It can be found here...

Two days ago in my physics class, one of my friends asked me a question: "There are 2 identical circular coils with radius 'r', length 'l' and 'n' no. of turns placed with their axes lying on a straight line, and current is let to pass through them so that mutual induction is observed.What...

My mum told me this one, it's pretty cool :). The red car and the blue car are having a race. The red car, which has a top speed of 70mph has a 20 minute head start over the blue car, which has a top speed of 80mph. Assuming that top speeds are reached the very instant a car starts, and...

So I've run into Einstein's Riddle... The answer is "The German" - but we're not done. What about the fact that only 2% of the world population will be able to solve the riddle? Say if you only considering the population in the USA, I'm quite sure at least 20% of the population should be...