Questions tagged [number-sequence]

A puzzle that asks for the pattern in a given number sequence.

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18
votes
1answer
1k views

How does this addition work (13+7=1130)?

I found this problem on 9gag and I have no idea how to solve it. Here is the question: $13+7=1130$ $88+9=47$ $32+28=2530$ $10+999=1149$ $444+77=61$ $55+111=56$ $21+0=1221$ $7+22=39$ $33+5=38$...
-1
votes
2answers
363 views

Percentage Puzzle question [closed]

There are two groups A and B with a value of 100 each. At the end of every day, group A gives 20% of it to group B while group B simultaneously gives 10 % of it to group A. So at the end of day 1, ...
4
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1answer
218 views

Next number in the sequence

Can you find the number that should be placed instead of the xxxx? 0000A... 0111AB.. ...
3
votes
1answer
213 views

What does this number sequence mean?

00 03 18 36 54 59 71 72 92 99 84 70 70 61 42 42 28 13 33 33 36 37 58 77 78 98 89 74 60 The number sequence represents a phrase, containing only lower-case letters ...
-1
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3answers
1k views

Complete the number-sequence

2 → 6 3 → 12 4 → 20 5 → 30 6 → 42 9 → ? Can you find a correspondence between these numbers? It's not mine, so I don't take any credit. I've just seen it in Linkedin and wanted to share with ...
5
votes
1answer
397 views

First Contact With Aliens

There is a strange meteor that is caught by the Earth's gravitational pull. No one even notices it because it is so small it will simply burn up in the atmosphere -- but it doesn't. Instead, it ...
2
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1answer
509 views

What does this mean?

What is the magic word? 011021042021011012012032012032014 Clues (Read, in order, one and re-think the problem): Five letter word 'A' equals 011051 Binary (Eight digit per) Compressed ...
26
votes
3answers
986 views

Why aren't the numbers playing nicely anymore?

The natural numbers have gotten in a big fight and split up into groups. If we can't get them back together again, the universe may never be the same! What kind of sense does it make to have three ...
1
vote
1answer
659 views

What is the next number in this puzzle [duplicate]

What is the relationship of this sequence and what is the answer for the last? 0001112359 = 4 1887145865 = 7 5528695874 = 6 0000085021 = 8 3247514251 = 0 5847962150 = ?
56
votes
1answer
3k views

Mysterious message from the NoSlaves™ Calculator Co

So my son is starting to show an interest in mathematics, and being the awesome dad that I am, I decided to buy him a basic calculator. Being the cheapskate that I am, I ordered the cheapest one I ...
3
votes
3answers
606 views

Find the combination algorithm

Once a month, Jerry visits the restaurant that he owns. Being paranoid that someone will steal his fortune, on each visit he changes the combination to his personal safe, which is hidden in the back ...
4
votes
2answers
291 views

Where do I end up?

Given this streak of numbers: 1 2 11 4 101 6 111 8 1001 10 1011 12 1101 14 1111 16 ? ? What will the last 2 numbers at the question marks be? Hint:
-4
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3answers
887 views

What's the Next number in series #3? [closed]

Find out the next number in following Simple series, 15, 55, 120, 210, 325, ?, ? Note: Question has many solutions.
2
votes
1answer
319 views

What's the next number?

In the following sequence, what is the next number and why? 11, 18, 26, 34, 35, 52, 67, 74, 78, 81 Hint:
2
votes
1answer
302 views

What's the Next number in series #1?

Can you find the next number in the below sequence 3 , 7 , 10 , 11 , 12 , 17 ? Note: if already asked please comment below, as I've searched for this but not ...
-2
votes
1answer
6k views

What is the next number and why? - 11,21,1112,… [duplicate]

Simple logic question, what is the next number and why? 11, 21, 1112, 3112, 211213, 312213, 212223, 114213, ?
19
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2answers
2k views

Ernie and the Alien Invasion

Yesterday I dropped in on Ernie to show off my new j-watch. Ernie wouldn't be impressed by instant wrist-mounted access to social media sites like me-tube, tweeter and farce-book so I thought I would ...
-1
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2answers
404 views

Number Sequence Puzzle [duplicate]

This is a slight variation on an old puzzle that's likely already here, but be sure to check it before you mark it as duplicate. What are the next three terms in this sequence, and why? ...
3
votes
1answer
1k views

Alphabet Number Matching

If : 888888 = T 777777 = O 555555 = Y 444444 = R then : 666666 = ? Basically you need to tell the logic along with ...
3
votes
1answer
492 views

Find the next number in this series

The sequence is: 4,7,7,0,1,1,4,8,3,2,3,9,4,1,5,3,0,6,4,5,0,5,1,0,9,1,2,7,7,1,4,9,5,5,6,9,5,1,? It's very simple indeed you won't need to do any calculation, but you may need to do a little one, ...
1
vote
1answer
1k views

Finish The Pattern #2

Given a pattern: 0, 1, 2, 0.5, 2, 3, 5, 1, 2, 0, 2, 1, 4, 2, 3, $n$ Find the next item at $n$. Pattern/sequence explanation required
0
votes
1answer
2k views

Finish The Pattern #1 [closed]

Given a pattern: 12, 22, 35, 68, 15, 28, 31, $n$ Find the next item at $n$. Pattern/sequence explanation required
2
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2answers
361 views

An Up and Down Series 00,50,33,25 . .

I won't provide a hint this time. This one is OEIS-proof (similar to waterproof :D) too. Twenty terms and guess its logic only. 00,50,33,25,20,16,14,12,11,10,90,83,76,71,66,62,58,55,52,50
4
votes
1answer
395 views

A sequence of integers

Here is my sequence (finite): 19,499,12991,337787,8782467,228344156,5936948059,154360649539. You just have to figure out its logic. Hint:
5
votes
1answer
228 views

A Sequence from a Sequence

This is a sequence that I made. I poured by blood and sweat into this! OK, no, it was more like orange juice and yogurt. It wasn't really all that hard, I guess. It might be tricky to figure out, ...
1
vote
2answers
183 views

A Sequence of Sequences

Originally, this question was way too wide open. I have tried to clarify / narrow it down / restrict the possibilities. Let me know if it is still too wide open. These are some number sequences. I ...
1
vote
2answers
476 views

Four rows of number sequences

Four rows of numbers: 1234567890 5916708234 192345678 ??? Fill in the last row with the appropriate digits (not necessarily 3, even though there are 3 '?'s). Please explain your answer. Hint/...
2
votes
1answer
754 views

What is the next number in sequence?

Consider the following sequence: 6211, 4214, 6321, 4135, 6359 What is the next number in that sequence? What are the rules of that sequence? I hope you'll enjoy my first question :) EDIT 1: ...
-6
votes
1answer
2k views

Determine the next two numbers in a number series

What are the next 2 numbers in the series 1, 1, 2, 4,6, 18, 21, 84, ?, ? Please give a valid reason to justify your answer.
-1
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3answers
2k views

What Comes Next?

Which number comes next in the sequence? 2, 7, 19, 47, 83, ___ Please remember to explain your reasoning and put your answer and reasoning behind spoilers. (Do >! and then your text to put one)
0
votes
1answer
267 views

Explain the sequence in these Excel Fill Series

In Excel Fill Series if you input 23, 132, 2 then 31.33333333, 20.83333333, 10.33333333, -0.166666667, -10.66666667....is generated and if you input 13, 16, 17 then 19.33333, 21.33333, 23.33333, ...
5
votes
2answers
863 views

A riddle by any other name

On his retirement, Bill Gates left behind a four number combination safe with a dial similar to this. In that safe is a secret that had eluded him many years ago...along with a small fortune of course....
10
votes
1answer
750 views

Continue the sequence

So my last riddle turned out to be too easy. Lets see if this one is difficult enough. You wake up with a huge headache and look around you. Somehow you managed to end up in a white room of about 2 ...
7
votes
2answers
470 views

Bitwise multiplication

Mr. EG has come up with a great coding scheme for (non-negative) integers in binary. To show off his creation, he demonstrates the following multiplications: ...
-4
votes
2answers
526 views

Solve the numeric sequence

I've thrown together some fun sequences to stretch your brains out! You can feel free to provide as many additional members of the sequence as you'd like, but mostly I'm looking to see if you can ...
8
votes
4answers
1k views

A crypto-sequence puzzle

Your Japanese co-worker from this problem hands you another piece of paper one day: 1820143 2383341 3245353 8425463 6354607 6627972 9088779 7839589 ??????? ??????? What two seven-digit ...
4
votes
4answers
2k views

Find the algorithm behind this repeating number sequence

During a garage sale I saw a strange old electronic device (not really, it's just flavor story). It had a battery slot, a button and a row of seven-segment displays - though from all except the two ...
25
votes
2answers
22k views

What is this magic trick with 6 cards featuring numbers between 1 and 60?

I hope this is on topic. I have a set of kids' magic tricks but I have lost the instructions! I was hoping this might be a good place to get some help. Here is the first one. What is the trick and ...
7
votes
2answers
2k views

Figure out this algorithm by analyzing the sequence of numbers generated

You are given a function f that, using an algorithm (that uses an old method), performs a calculation on four distinct values _ and generates a sequence of ten numbers. Now, your task is to figure ...
6
votes
8answers
50k views

Fill the holes? [closed]

You have to fill the boxes to make the equation true:   +   +   = 30 Using only 1, 3, 5, 7, 9, 11, 13, 15. You can also repeat the numbers. (eg: 1 + 1 + 1) Edit1: the boxes of the equation are ...
8
votes
5answers
1k views

A tricky batch of four number sequences

What are the next few numbers in each of these integer sequences? Each of them has a clear and justifiable solution. 1, 2, 3, 5, 8, 9, 12, 20, 21, 22, ??, ??, ... 50, 49, 48, 46, 45, 44, 43, ...
1
vote
3answers
861 views

Lalozik Pattern

Vasily Lalozik is a professional cryptographer and develops new security schemes for banks. But he has one problem: David Banes. The American Bank is the largest bank in the world; Banes has his ...
16
votes
1answer
667 views

Sorcery squares!

The following 5-by-5 squares of digits are not magic squares, but nevertheless they each have a crucial property which enabled me to generate them. What is that property? How could you generate more ...
32
votes
2answers
3k views

Ancient machine in the desert… how does it generate its output?

I was walking through the desert and came across an ancient contraption of cogs and gears. It had a series of dials on one side that appeared to allow the input and output of numbers. On the other ...
2
votes
1answer
7k views

Math Number Sequence Riddle with 4 numbers 8 digits [duplicate]

Create a number using only the digits 4,4,3,3,2,2,1 and 1. So it can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits, the threes ...
4
votes
3answers
1k views

A simple but most devious sequence puzzle

This is a question from a previous, now-defunct version of the Temple of Quetzalcoatl, that I've posted here as an exemplar of one of the difficult puzzles you might encounter while solving it. The ...
12
votes
3answers
2k views

Three different, and somewhat difficult, sequence puzzles

Here are three different letter/number sequences. Try to solve as many as possible. The spoilers give hints to each sequence in the form of how many elements are in the corresponding sequence. ...
9
votes
5answers
2k views

Another one of those odd sequence puzzles

This is an interesting one. I will do the same thing that I usually do. After one week, a hint. After 2 weeks, a hint. After 3 weeks, an answer. I may change this system. What number goes in the ...
9
votes
2answers
2k views

What is the next term in the sequence?

The first term is f(0), the last term is f(2000): 0,0,0,0,1,0,1,0,2,1,1,0,2,0,1,1,3,0,2,0,2,1,1,0,3,1,1,2,2,0,2,0,4,1,1,1,3,0,1,1,5,0,2,0,2,2,1,0,4,1,2,1,2,0,3,1,5,1,1,0,3,0,1,2,6,1,2,0,2,1,2,0,4,0,1,...
7
votes
1answer
204 views

Find the replacement for `?`

624 --> 20 532 --> 117 634 --> 152 723 --> 40 443 --> 175 825 --> ? What should be filled in the last place so as to maintain the ...