Permutation and CombinationEasy
Question
On the occasion of Dipawali festival each student of a class sends greeting cards to the others. If there are 20 students in the class, then the total number of greeting cards exchanged by the students is-
Options
A.20C2
B.2.20C2
C.2.20P2
D.None of these
More Permutation and Combination Questions
Six identical coins are arranged in a row. The number of ways in which the number of tails is equal to the number of hea...The number of five digit numbers that can be formed using all the digits 0, 1, 3, 6, 8 which are -...The number of permutations formed without changing the position of vowel and consonants of the letters of word ′AL...Number of ways of placing 5 identical balls in 3 identical boxes (no box remains empty), is -...A boat crew consist of 8 men, 3 of whom can only row on one particular side and 2 only on the other. The number of ways ...