Combinations and Permutations Combinations and Permutations

Combinations and PermutationsCombinations and Permutations

Click here to view more Kerala PSC Study notes.

Permutation and combination related questions are common in PSC and Bank exams.

Before going to Combinations and Permutations, first lean about factorial.

If \'n\' is a positive integer then, factorial of n is denoted as n!.

5! = ( 1 x 2 x 3 x 4 x 5 ) = 120

4! = (1 x 2 x 3 x 4 ) = 24

Permutations are for lists of items, whose order matters and combinations are for group of items where order doesn’t matter. in other words,

  • When the order of items doesn\'t matter, it is called as Combination.
  • When the order of items does matter it is called as Permutation.

The number of permutations of n objects taken r at a time is determined by using this formula:


Permutation: Listing your 3 favourite football team in order, from list of 10 teams. P(10,3) = 720.

The number of combinations of n objects taken r at a time is determined by using this formula:


Combination: Picking a team of 3 people from a football coaching group of 10. C(10,3) = 10!(3!(10−3)!) = 120.

Click here to search study notes. Click here to view all Kerala PSC Study notes. Click here to read PSC Question Bank by Category wise. Click here to Test your knowledge by atteneding Quiz.

Nobel Prize Winners 2020



The Royal Swedish Academy of Sciences has decided to award the 2020  Nobel Prize in Physics with one half to Roger Penrose and the other half jointly to Reinhard Genzel and Andrea Ghez. Half of the Nobel prize went to Roger Penrose for the "discovery that black hole formation is a robust prediction of the general theory of relativity”, and the other half went to Reinhard Genzel and Andrea Ghez for the "discovery of a supermassive compact object at the centre of our galaxy”,  .

ഐന്‍സ്റ്റീന്റെ സാമാന്യാപേക്ഷികതാ സിദ്ധാന്തമനുസരിച്ചാണ് തമോഗര്‍ത്തങ്ങള്‍ രൂപപ്പെടുന്നതെന്ന് ഗണിത ശാസ്ത്രമോഡല്‍ ഉപയോഗിച്ച് തെളിയിച്ചതിനാണ് റോജര്‍ ...


Famous slogans in indian independence


ഇന്ത്യൻ സ്വാതന്ത്ര്യത്തിലെ പ്രസിദ്ധമായ മുദ്രാവാക്യങ്ങൾ .

ഇൻക്വിലാബ് സിന്ദാബാദ് മുഹമ്മദ് ഇക്ബാലാണ് ഈ മുദ്രാവാക്യത്തിന്റെ ഉപജ്ഞാതാവ്. ആദ്യമായി മുഴക്കിയത് ഭഗത്സിംഗ്. .
പ്രവർത്തിക്കുക അല്ലെങ്കിൽ മരിക്കുക ഗാന്ധിജി .
ജയ്ഹിന്ദ്. ചലോ ദില്ലി സുഭാഷ് ചന്ദ്രബോസ് .
സ്വരാജ്യം എന്റെ ജന്മാവകാശമാണ് ബാലഗംഗാധര തിലക് .
സത്യവും അഹിംസയുമാണ് എന്റെ ദൈവങ്ങൾ ഗാന്...


Famous Scientists and Inventors


Albert Einstein : Came up with the Theory of Relativity and the equation E=mc^2.
Alexander Graham Bell : Invented the telephone.
Antoine Lavoisier : Father of modern chemistry.
Ben Franklin : Inventor and Founding Father of the United States.
Francis Crick and James Watson : Discovered the structure of the DNA molecule.
Galileo : First used the telescope to view the planets and stars.
George Washington Carver : Botanist who was called the "farmers best friend.".
Henry Ford : Invented the Model T Ford, the first mass produced car.
Isaac Newton : Discovered the theory of gravity and the three laws of motion.
Jane Goodall : Studied chimpanzees in the wild for many years.
Johannes Gutenberg : Invented the printing press.
Leonardo da Vinci : Inventor and artist from the Renaissance.
Louis Pasteur : Discovered pasteurization, vaccines, and founded the science of germ theor...