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Questions tagged [number-property]

Puzzles that use number properties such as even and odd, multiples of numbers, part of a well-known sequence (i.e. Fibonacci) or theorem (Pythagorean relations) or others in part of the method to solve the question.

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3
votes
0answers
142 views

What is an IJKLMN Number™?

This is in the spirit of the What is a Word/Phrase™ series started by JLee with Number version puzzles. If a number conforms to a special rule, I call it an IJKLMN Number™. Use the following examples ...
9
votes
3answers
559 views

Discover the six-character password!

You are given several pieces of paper which are as follows: (Unfortunately, a textual rendering is very difficult with this puzzle, so if someone can offer a suggestion on how to do it, that would be ...
-2
votes
1answer
142 views

Which number belongs where?

...
-1
votes
1answer
72 views

Number whose letters are in alphabetical order [duplicate]

Can you find the smallest number whose letters are in alphabetical order when spelled out in English?
-3
votes
1answer
49 views

Find missing number in the transformation 2 [duplicate]

Can you find the missing number? This number has a single digit. 1 → 3 3 → 5 5 → 4 4 → ? Good luck!
9
votes
2answers
353 views

What is an Encoding Number™?

This is in the spirit of the What is a Word/Phrase™ series started by JLee with Number version puzzles. If a number conforms to a special rule, I call it an Encoding Number™. Use the following ...
5
votes
2answers
249 views

Find missing number in the transformation

Can you find the missing number? This number has a single digit. 8 → 7 7 → 3 3 → 5 5 → ? Good luck!
11
votes
1answer
451 views

What is a Heptagon Number™?

This is in the spirit of the What is a Word/Phrase™ series started by JLee with Number version puzzles. If a number conforms to a special rule, I call it a Heptagon Number™. Use the following ...
29
votes
1answer
1k views

What is a BEN Number™?

This is in the spirit of the What is a Word/Phrase™ series started by JLee with Number version puzzles. If a number conforms to a special rule, I call it a BEN Number™. Use the following examples ...
7
votes
2answers
917 views

What is a Finale Number™?

This is in the spirit of the What is a Word/Phrase™ series started by JLee with Number version puzzles. If a number conforms to a special rule, I call it a Finale Number™. Use the following examples ...
13
votes
1answer
250 views

What is a Hope & Love Number™?

This is in the spirit of the What is a Word/Phrase™ series started by JLee with Number version puzzles. If a number conforms to a special rule, I call it a Hope & Love Number™. Use the following ...
9
votes
3answers
306 views

Know your primes

Did you know that a prime, regardless of its base, is always a prime? I am looking for a prime. It’s the largest of its kind. In solving this puzzle, the answer you may find. ...
7
votes
1answer
182 views

Bravetart: Iconic America

It's been a while since I've posted, and in the spirit of my recent works, I've got a simple riddle to get back into the swing of things. As always, I hope you enjoy it, and best of luck! After the ...
1
vote
0answers
191 views

Numbers in this table?

I found this table, but can't seem to find any relation between the numbers. Also there is not much logic involved. ...
0
votes
1answer
115 views

What is the missing number in the box

I found some online number puzzle as below: My guess was 436 (go up by 118 again, as the left & right go up by 1) but apparently it was incorrect. I cannot see any other patterns, any ideas?
6
votes
1answer
217 views

I'm a Proper Divisor

Ann and Bob are playing a number game. Ann starts with the number 60. Then she subtracts a proper divisor of 60 from it. Bob then takes the number Ann made and subtracts one of its proper divisors ...
14
votes
3answers
627 views

Hiker's Cabin Mystery | Pt. II

See Part I | See Part III Nice one, @GarethMcCaughan! Finally, you've gotten into his computer using the password you managed to decode from his clues... but there's another issue! There is a ...
10
votes
1answer
574 views

I'm thinking of a number

The unusual thing about this number is that the most common phrases that use it are wrong. That is, while someone may often say there are X As in a B, the actual number is not X. What number am I ...
9
votes
1answer
171 views

What's the significance of this pattern?

Note, this is my first submission, let me know if I broke the rules. What is the significance of the following sequence of # signs? ...
4
votes
5answers
429 views

Haters will say 28 June

Find the next number in this sequence: $4,3,7,5,10,15,?$ Think outside the frustum here. Hint 1: Hint 2:
9
votes
8answers
1k views

What mysterious whole number am I?

From my second point of view I copy that amount of first. I am the dominant side of two but for many I'm the worst. I'll be tricky to find but today might be your day, after all my neighbour is 2/3 of ...
9
votes
2answers
1k views

Ten-digit number that satisfy divisibilty rules for 2,3,4,5,6,7,8,9,10&11

Question: Arrange the digits 1,2,3,4,5,6,7,8,9,0 to make a ten-digit Number that satisfies all of the divisibility rules for 2,3,4,5,6,8,9,10,&11. BONUS: make the number also divisible by 7
5
votes
2answers
276 views

Using 20, 17, 16, 8, 7 to make 9

You can use $+, -, \times, $ or $/$ (namely $\div$). Use all five numbers (20, 17, 16, 8, and 7) only once to make $9$. From what I've been told there are $4$ answers. The only one I've been able ...
8
votes
4answers
441 views

A “Find the Path” Puzzle

I invented a puzzle, inspired by Simon Tatham's Portable Puzzle Collection. Is there anything that it could improve on? Was it too easy, or was it too hard? Anything I could add? What must I call it? ...
6
votes
8answers
548 views

Make $1,\dots,15$ using $3, 9, 9, 9$

This was inspired by many puzzles that use three/four numbers to create other numbers. I chose these numbers in particular because of this post. Can you find a way to make all the natural numbers ...
8
votes
2answers
238 views

Half and Double Value

A 3 year old child tried to input or copy a number (written on the paper) to a calculator but he messed up with the digit places. All the digits are there but the value of the number he inputed ...
12
votes
1answer
237 views

What is a Voluminous Number™?

In the spirit of the What is a Word™/Phrase™ series started by JLee, a special brand of Phrase™ and Word™ puzzles. If a number conforms to a special rule, I call it a Voluminous Number™. Use the ...
2
votes
3answers
412 views

72 + 96 = 120, is it possible?

I came across the following riddle: How is it possible for $72+96=120$ to be correct?
4
votes
1answer
222 views

systematic number removal [duplicate]

The whole, natural numbers 1 through 50 are written on a board. The following operation is performed 49 times: select any two of the numbers on the board and write the absolute value of their ...
17
votes
3answers
6k views

Which two students spoke wrongly? [duplicate]

A teacher wrote a large number on the board and asked the students to tell about the divisors of the number one by one. The 1st student said, "The number is divisible by 2." The 2nd student said, "...
6
votes
1answer
238 views

What do numbers have?

Numbers 0 through 9 each have a number of something. 0 has 6. 1 has 2. 2 has 5. 3 has 5. 4 has 4. How many do 5, 6, 7, 8 and 9 have?