The Mystery Six-Digit Number

Find a six-digit number containing no zeros and no repeated digits that satisfies the following conditions:

1. The first and fourth digits sum to the last digit, as do the third and fifth digits.
2. The first and second digits when read as a two-digit number equal one quarter the fourth and fifth digits.
3. The last digit is four times the third digit.

192768.

If you call the number ABCDEF, then you get the following equations.

1. A + D = F and C + E = F
2. AB = DE / 4
3. F = 4 × C

The only numbers that work for C and E are 2 and 6 or 4 and 8, and in order to make F a single-digit number, we can deduce that C = 2, E = 6 and F = 8.

So far, our number is AB2D68.

We know A + D = 8 so A and D are both odd numbers. The only odd number less than 8 that we can use for D to make one-quarter of two-digit number D6 also be a two-digit number is 7, so D = 7 and A is 1. This makes the two-digit number AB 19.

Posted in Brain Teasers

4 5 6 6

What is the next digit that should appear in this list of numbers?

4 5 6 6 5 4 4 2 ?

7. The digits represent the number of letters in each word of the puzzle. “What” has four letters, “digit” has five letters, “should” has six letters, etc. The last word is “numbers” which has seven letters.

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Takeoff On a Conveyor Belt

If a plane sits on a conveyor belt whose speed matches that of the plane in the opposite direction, can the plane take off?

Yes, because a plane’s wheels roll freely and have no affect on the movement of the plane(unlike a car). The propeller or jet engine makes the plane move and the plane will be able to take off normally. If you don’t believe me, here’s proof.

Posted in Brain Teasers

Apples, Ice and Flowers

Apples, ice, and flowers can do it.
Pears, stones, and coins can’t.

Float.

By Sef Daystrom

Posted in Riddles

Longest Word in English

What is the longest word in the English dictionary?

Smiles because there is a mile between the two s’s.

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My Thunder, Lightning and Rain

My thunder comes before the lightning.
My lightning comes before the clouds.
My rain dries all the land it touches.

What am I?

A volcano.

(via Reddit)

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Walks on Graves at Night

This walks on graves at night yet in homes during the day,
Men are scared of it, women like it, children play with it,
It lives on dates and salt,
It is covered in hair,
Its name starts with ‘M’ and it is mentioned in the Quran.

What is it?

Moths.
Most species of moths are nocturnal, yet they are attracted to light and can be found in homes. Men, in the most generic sense, can be scared of moths (see Mottephobia) as well as the damage they can cause as pests to bee hives, grain, flour, trees and agriculture. Women like moths because of the silk they produce. Children frequently chase and play with moths. Moths are attracted to salt and love to eat rotting fruit (such as dates). Some species of moths are densely covered with tiny hairs and of course it starts with the letter ‘m’. Lastly, moths are mentioned in the Quran (101:4 (Asad) [It will occur] on the Day when men will be like moths swarming in confusion)

Posted in Riddles

Reading Hexadecimal

How many people can read hexadecimal if only you and dead people can read it?

57006

The trick is that the word “dead” represents a number in hexadecimal. That number in base 10 is 57005, and adding one more to include yourself gives you: 57005 + 1 = 57006.

Posted in Brain Teasers

Two Faces But Show You One

I have two faces, but show you one.
I once had guests, but now have none.
I’m rarely bloody and seldom blue.
I’m often promised and sometimes new.

The moon. It has two sides, but on earth we only ever see one side. Man has been on the moon, but no one is there now. A full lunar eclipse is known as a blood moon, and the phrase “once in a blue moon” refers to something that rarely happens. Promising the moon is making an extravagant or impossible promise, and there’s a new moon once every lunar cycle.

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Arms and Legs But No Head

What has arms and legs but no head?

A chair.

Posted in Riddles