Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [recreational-mathematics]

Mathematics done just for fun, often disjoint from typical school mathematics curriculum. Also see the [puzzle] and [contest-math] tags.

Recreational mathematics is a general term for mathematical problems studied for the sake of pure intellectual curiosity, or just for the enjoyment of thinking about mathematics, without necessarily having any practical application or expectation of deep theoretical results.

Recreational mathematics problems are often easy to understand even for people without an extensive mathematical education, even if the theory they lead to may turn out to be surprisingly deep. Thus, recreational mathematics can serve to attract the curiosity of non-mathematicians and to inspire them to develop their mathematical skills further.

Many typical recreational mathematics problems fall into the fields of discrete mathematics (combinatorics, elementary number theory, etc.), probability theory and geometry. Important contributors to recreational mathematics are Sam Loyd and Martin Gardner.

5128 questions
0
votes
1 answer

Form $4$ new symbols with the most common symbols

Suppose we have $6$ symbols, say $A,B,C,D,E,F$. We are asked to form $4$ new symbols using the $6$ symbols with the addition operation. For example, the $4$ new symbols can be $A+C+E, F+E+A, D+C+A, A+F+D$. There are some restrictions on the…
Idonknow
  • 15,643
0
votes
3 answers

Completing the square for a quartic expression

By completing the square, find (for real $x$) the minimum value of: $$x^4 + 2x^2 + 2.$$
Roger
  • 9
0
votes
3 answers

what will be the answer either 30 or 31 for this time based question?

A red light flashes 3 times per minute and a green light flashes 5 times in two minutes at regular intervals. If both lights start flashing at the same time, how many times do they flash together in each hour? according to me solution is Red light…
Tanish Gupta
  • 19
  • 4
0
votes
2 answers

IS the sequence right?

What i think is that, the sequence isn't correctly formulated. I have tried like this 7x5-9=35 2x3-1=5 8x6-4=44 4x5-9=?=11
user52950
0
votes
1 answer

Finding average speed

Your must reach from point A to point B in 20 minutes. Distance between the two points in 9.95 miles. 3 miles from point A, there is a tunnel the length of the tunnel is 1.2 miles. Inside the tunnel, you can only go 15 mph and under. What is the…
user50372
  • 1
0
votes
2 answers

Another cool logical brain teaser I used to work when on when I was small

A person has 3 cups with him , he has a 8L cup filled with coke , and an empty 5L and 3L cups, using these three can anyone make 2 cups each with 4L to be served to two people. This person has no measuring instruments and assume that things like…
M.S.E
  • 1,857
0
votes
1 answer

How can I transition my dogfood can opening procedure from the morning to the evening?

My 2 dogs are each fed twice a day. They are each given 1/4 can of dog food with every feeding: 1/2 a can a day per dog; 1 can consumed total, daily. To prevent me from having to manage opening a new can in the mornings, I open a new can of dog food…
JoshDM
  • 103
0
votes
1 answer

What is the subset of the letters in the word 'numbers'

What is the subset of the letters in 'numbers'? I thought it meant to make a word out of the letters in 'numbers' so I tried to make a word out of it, but I couldn't make a word and so I don't understand the task. Please help me this is my…
David
  • 1
0
votes
1 answer

Find the width of the river.

Q) 2 boats are crossing the river from opposite sides. When they first meet, they are 720m from the near shore. When they reach the opposite shore, they stop for 10mins and cross the river again, but this time they meet 400m from the other shore.…
Harshal Gajjar
  • 1,664
0
votes
3 answers

How many persons do you think are liar?

There are 10 person. First person says: At least one of the person is liar. Second person says: At least two of the person is liar. Third person says: At least three of the person is liar. Fourth person says: At least four of the person is…
user136567
0
votes
2 answers

Is There An Alternative To Using 0 As A Placeholder?

I'm no math wiz here, but I have a question that I can't wrap my head around. In fact, I don't even know how I would even go about asking the question properly. Is there an alternative to using 0 as a placeholder? When writing out numbers, 10…
Xarcell
  • 171
  • 1
  • 6
0
votes
1 answer

25 coins are arranged in a 5 by 5 array.

25 coins are arranged in a 5 by 5 array. A fly lands on one and tries to hop on to every coin exactly once, at each stage moving only to an adjacent coin in the same row or column. Is this possible?
nilla mitra
  • 1
0
votes
1 answer

12 base units instead of 10

Why do we use 10 as a whole unit when it can't be evenly divided by 3 or 6 without resulting in an infinite decimal I.e 3.3333etc. If units of 12 were used I.e 1 2 3 4 5 6 7 8 9 ? # 10. 3.3333 would become 3.4 (10/3=3.4) In math, I'm told, if you…
David Thomas
  • 1
0
votes
1 answer

Why all near integers

$C$MRB is a symbol for the MRB constant. Why do I get all near 0, 1 or 2 for all values of n for sin(Pi/$C$MRB*(5060936308 + 78389363/24*Floor(n)))? The results near 0 are very small and the arguments are all very large! With Mathmatica let m be…
Marvin Ray Burns
  • 301
0
votes
2 answers

How to better compute this eta formula

In the question MRB constant proofs wanted , I gave the following excerpt from http://marvinrayburns.com/UniversalTOC25.pdf . . I accurately worked formula 44 in Matheamatica in the following code. (*define the eta function*) eta[s_] := (1 - 2^(1…
Marvin Ray Burns
  • 301
1 2 3
…
35 36