If every one of 10 people shakes hands once with each other, how many handshakes occur?
A90
B100
C45
D55
Answer & Solution
Correct answer: C. 45
Each handshake is an unordered pair, so 10C2 = 45.
Keep practising Permutations and Combinations
Browse all Permutations and Combinations questions for CA Foundation, or explore more Quantitative Aptitude topics.
Related questions
How many permutations of 1, 2, 3 leave no number in its own position?In how many ways can 6 identical sweets go to 2 children, a child may get none?Six distinct people are split into two unlabelled groups of 3. How many ways?A team of 4 is chosen from 10 players and one named player must be included. How many waysHow many 5-digit numbers using digits 1 to 5 once each are divisible by 4?Letters of DELHI are arranged with the two vowels together. How many arrangements?In how many ways can at least one item be selected from 5 distinct items?Pick 3 of 6 red balls and 2 of 5 blue balls. How many different selections?