Home › CBSE Class 11 (Commerce) › Mathematics › Permutations and Combinations › Twelve people each shake hands once with every o…
Twelve people each shake hands once with every other. How many handshakes occur?
A24
B132
C144
D66
Answer & Solution
Correct answer: D. 66
A handshake is an unordered pair, so the count is 12C2 = 66.
Related questions
Al-Khalil's cryptography book listed words using which idea?A permutation of a finite set is what kind of function on that set?A k-combination of a set S is best described as what?Cauchy's 1815 memoir on substitutions of n elements led to which notion?Which Chinese text used permutation-like hexagrams as early as 1000 BC?How many elements does the symmetric group on 4 objects contain?In how many ways can the letters of BANANA be arranged?A multiset permutation uses each element how many times?