# 10 most difficult mathematics riddles

A list of ten (out of 58) mathematics related questions that are the most often answered incorrectly

Mathematics quiz
## How is the infinity symbol called?

Lemniscate refers not only to the infinity symbol but also to any geometric shape that is curved like a figure-eight.

very hard

17%

lemniscate

lemniscate

17%

omniscate

omniscate

61%

perniscate

perniscate

11%

ettoniscate

ettoniscate

8%

Created by: Ninjai.
Statistics based on 474 answers in 3 languages
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## Which mathematician is it?

Henri Poincaré. Jules Henri Poincaré was a French mathematician, theoretical physicist, engineer, and philosopher of science. He is often described as a polymath, and in mathematics as " The Last Universalist"n since he excelled in all fields of the discipline as it existed during his lifetime. He was responsible for formulating the Poincaré conjecture, which was one of the most famous unsolved problems in mathematics until it was solved in 2002–2003 by Grigori Perelman. In his research on the three-body problem.

very hard

23%

Grigory Perelman

Grigory Perelman

8%

Gottfried Wilhelm Leibniz

Gottfried Wilhelm Leibniz

34%

Henri Poincaré

Henri Poincaré

23%

Stefan Banach

Stefan Banach

33%

Created by: Tschuka .
Statistics based on 494 answers in 2 languages
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## The illustration shows the figure known in mathematics as;

Lune of Hippocrates,. In geometry, the lune of Hippocrates, named after Hippocrates of Chios, is a lune bounded by arcs of two circles, the smaller of which has as its diameter a chord spanning a right angle on the larger circle. Equivalently, it is a non-convex plane region bounded by one 180-degree circular arc and one 90-degree circular arc. It is the first curved figure to have its exact area calculated mathematically.

very hard

24%

Tales' sails

Tales' sails

25%

Pythagorean sickles

Pythagorean sickles

23%

Archimedes' arches

Archimedes' arches

25%

lune of Hippocrates,

lune of Hippocrates,

24%

Created by: Tschuka .
Statistics based on 243 answers in 2 languages
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## Which of the following is true for the solution with the pH=0?

The OH − ion concentration is smaller than the H+ ion concentration. In chemistry, pH is a numeric scale used to specify the acidity or alkalinity of an aqueous solution. It is the negative of the logarithm to base 10 of the activity of the hydrogen ion .Traditionally the pH is being defined as: pH = - log10 [H+], where [H+] it is a H+ ions concentration in mol/dm^3 (M). So if pH = 0 this H+ ions concentration is 1 mol/dm^3 and the solution is strongly acidic.

very hard

25%

the OH − ion concentration is smaller than the H+ ion concentration

the OH − ion concentration is smaller than the H+ ion concentration

25%

the OH − ion concentration is greater than the H+ ion concentration

the OH − ion concentration is greater than the H+ ion concentration

19%

the OH − ion concentration is equal of the H+ ion concentration

the OH − ion concentration is equal of the H+ ion concentration

28%

Such solution doesn't exist

Such solution doesn't exist

26%

Created by: Paweł Kołodziejczyk.
Statistics based on 3381 answers in 2 languages
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## Which of the following Roman numerals stands for 4?

Both IV and IIII. Both notations are correct and historically Roman numerals were often written less consistently than today. The notation 'IIII' is often seen on clock faces. The reason for that may be practical, to avoid confusing the IV and VI when the clock is held upside down (although other theories also exist).

very hard

26%

IV

IV

71%

IIII

IIII

1%

Both IV and IIII

Both IV and IIII

26%

None of the above

None of the above

1%

Created by: globalquiz.org.
Statistics based on 6362 answers in 4 languages
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## A given natural number is divisible by 4 if and only if ...?

The number created from the last two digits is divisible by 4. The last two digits form a number that is divisible by 4; 40,832: 32 is divisible by 4. If the tens digit is even, the ones digit must be 0, 4, or 8. If the tens digit is odd, the ones digit must be 2 or 6. 40,832: 3 is odd, and the last digit is 2. Twice the tens digit, plus the ones digit is divisible by 4.

very hard

27%

the last digit is divisible by 4

the last digit is divisible by 4

15%

the last two digits are divisible by 4

the last two digits are divisible by 4

32%

the sum of the last two digits is divisible by 4

the sum of the last two digits is divisible by 4

23%

the number created from the last two digits is divisible by 4

the number created from the last two digits is divisible by 4

27%

Created by: Tschuka .
Statistics based on 651 answers in 2 languages
»

## Which mathematician laid the foundations for abstract algebra (especially the group theory)?

Évariste Galois was a French mathematician born in Bourg-la-Reine. While still in his teens, he was able to determine a necessary and sufficient condition for a polynomial to be solvable by radicals, thereby solving a problem standing for 350 years. His work laid the foundations for Galois theory and group theory, two major branches of abstract algebra, and the subfield of Galois connections. He died at age 20 from wounds suffered in a duel.

very hard

30%

Évariste Galois

Évariste Galois

30%

Stefan Banach

Stefan Banach

31%

David Hilbert

David Hilbert

22%

Bertrand Russell

Bertrand Russell

16%

Created by: Ninjai.
Statistics based on 1382 answers in 3 languages
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## What is the largest integer ever used in a mathematical proof?

Graham's number is an enormous number that arises as an upper bound on the answer of a problem in the mathematical field of Ramsey theory. The number was published in the 1980 Guinness Book of World Records, adding to its popular interest.

very hard

31%

Googolplex

Googolplex

13%

Googol

Googol

38%

Graham's number

Graham's number

31%

Centillion

Centillion

17%

Created by: Ninjai.
Statistics based on 3756 answers in 2 languages
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## Which numeral system was in use in ancient Sumer and Babylon?

Sexagesimal. Remnants of highly composite sexagesimal system are in use even today for measuring angles, geographic coordinates and especially time. An hour of time is divided into 60 minutes, which in turn are divided into 60 seconds.

very hard

32%

octal

octal

22%

binary

binary

20%

decimal

decimal

24%

sexagesimal

sexagesimal

32%

Created by: smyru.
Statistics based on 13709 answers in 2 languages
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## What is the base value of the natural logarithm?

Napier's constant. The natural logarithm of a number is its logarithm to the base of the mathematical constant e (Euler's number), occasionally referred to as Napier's constant. The common logarithm is the logarithm with base 10, while the binary logarithm is the logarithm with base 2.

very hard

32%

Napier's constant

Napier's constant

32%

10

10

30%

number π

number π

20%

2

2

16%

Created by: Ninjai.
Statistics based on 739 answers in 2 languages
»

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