Hard riddles

logicmath

24 from Spare Parts

Using only and all the numbers 3, 3, 7, 7, along with the arithmetic operations +,-,*, and /, can you come up with a calculation that gives the number 24? No decimal points allowed. [For example, to get the number 14, we could do 3 * (7 - (7 / 3))]
7 * ((3 / 7) + 3) = 24
86.91 %
43 votes

logicshort

Six rungs

A boat has a ladder that has six rungs, each rung is one foot apart. The bottom rung is one foot from the water. The tide rises at 12 inches every 15 minutes. High tide peaks in one hour. When the tide is at it's highest, how many rungs are under water?
None, the boat rises with the tide.
86.91 %
43 votes

cleanlogicwhat am I

Wordplay

What word in the English language does the following: the first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?
Heroine
86.81 %
31 votes

funny

Superior mother

A man came to visit at a convent while the superior mother was out of town. He left before she returned, and was careful to leave nothing behind. The nuns said nothing about his visit, so how did the superior mother figure out that a man had been there?
Because a toilet seat was up.
86.62 %
42 votes

cleanlogicshort

8 letter word

What 8 letter word can have a letter taken away and it still makes a word. Take another letter away and it still makes a word. Keep on doing that until you have one letter left. What is the word?
The word is starting! starting, staring, string, sting, sing, sin, in, i.
86.62 %
63 votes

logic

Six jugs in a row

Six jugs are in a row. The first three are filled with coke, and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?
Move and then pour all coke from second glass to fifth glass.
86.32 %
41 votes

logic

Dead in Water and Glass

Romeo and Juliet are found dead in a small puddle of water, surrounded by broken glass. The apartment building they are found in is located next to the city's main train station. How did they die?
Romeo and Juliet are fish. A passing train rattled the shelf their tank was sitting on and knocked it off of the shelf. The tank broke and the fish died from being out of the water.
86.32 %
41 votes

logic

Gambling house

Even though the odds are always in favor of the gambling house, why does the establishment insist on a house limit on stakes?
Every casino in the world would go bankrupt without a house limit on stakes. Without it, gamblers would keep doubling their stakes until they won. No matter how bad a losing streak they were on, they would eventually win.
86.32 %
41 votes

logicmath

One equals two

Consider the following explanation for why 1=2: 1. Start out Let y = x 2. Multiply through by x xy = x2 3. Subtract y2 from each side xy - y2 = x2 - y2 4. Factor each side y(x-y) = (x+y)(x-y) 5. Divide both sides by (x-y) y = x+y 6. Divide both sides by y y/y = x/y + y/y 7. And so... 1 = x/y + 1 8. Since x=y, x/y = 1 1 = 1 + 1 8. And so... 1 = 2 How is this possible?
Step 5 is invalid, because we are dividing by (x-y), and since x=y, we are thus dividing by 0. This is an invalid mathematical operation (division by 0), and so by not followinng basic mathematical rules, we are able to get strange results like these.
86.32 %
41 votes