80 (number)

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Cardinal eighty
Ordinal 80th
(eightieth)
Factorization 24× 5
Divisors 1, 2, 4, 5, 8, 10, 16, 20, 40, 80
Greek numeral Π´
Roman numeral LXXX
Binary 10100002
Ternary 22223
Quaternary 11004
Quinary 3105
Senary 2126
Octal 1208
Duodecimal 6812
Hexadecimal 5016
Vigesimal 4020
Base 36 2836

80 (eighty) is the natural number following 79 and preceding 81.

In mathematics[edit]

80 is:

The Pareto principle (also known as the 80-20 rule) states that, for many events, roughly 80% of the effects come from 20% of the causes.[3][4]

Every solvable configuration of the Fifteen puzzle can be solved in no more than 80 single-tile moves.[5]

In science[edit]

Element 80: Mercury (Hg)

In religion[edit]

  • According to Exodus 7:7, Moses was 80 years old when he initially spoke to Pharaoh on behalf of his people. Today, 80 years of age is the upper age limit for cardinals to vote in papal elections.

In other fields[edit]

Eighty is also:

See also[edit]

References[edit]

  1. ^ "Sloane's A005835 : Pseudoperfect (or semiperfect) numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-29. 
  2. ^ "Sloane's A000179 : Ménage numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-29. 
  3. ^ Bunkley, Nick (March 3, 2008). "Joseph Juran, 103, Pioneer in Quality Control, Dies". The New York Times. .
  4. ^ "What is 80/20 Rule, Pareto's Law, Pareto Principle". Archived from the original on 2013-01-28. Retrieved 2017-05-20. .
  5. ^ A. Brüngger, A. Marzetta, K. Fukuda and J. Nievergelt, The parallel search bench ZRAM and its applications, Annals of Operations Research 90 (1999), pp. 45–63.

External links[edit]