Advertisements
Advertisements
Question
The number of permutation of n different things taken r at a time, when the repetition is allowed is ______.
Options
rn
nr
`(n!)/((n - r)!)`
`(n!)/((n + r)!)`
Advertisements
Solution
The number of permutation of n different things taken r at a time, when the repetition is allowed is nr.
Explanation:
The correct answer is nr because when repetition is allowed, each of the r positions can be filled by any one of the n different objects. Thus, the total number of possible permutations is n × n × ... × n = nr.
APPEARS IN
RELATED QUESTIONS
Compute `(8!)/(6! xx 2!)`
How many words, with or without meaning can be made from the letters of the word MONDAY, assuming that no letter is repeated, if
(i) 4 letters are used at a time,
(ii) all letters are used at a time,
(iii) all letters are used but first letter is a vowel?
In how many of the distinct permutations of the letters in MISSISSIPPI do the four I’s not come together?
If three six faced die each marked with numbers 1 to 6 on six faces, are thrown find the total number of possible outcomes ?
If in a group of n distinct objects, the number of arrangements of 4 objects is 12 times the number of arrangements of 2 objects, then the number of objects is
How many five digits telephone numbers can be constructed using the digits 0 to 9 If each number starts with 67 with no digit appears more than once?
Three men have 4 coats, 5 waist coats and 6 caps. In how many ways can they wear them?
In how many ways can the letters of the word SUCCESS be arranged so that all Ss are together?
In how many ways can 5 children be arranged in a line such that two particular children of them are always together
There are 10 persons named P1, P2, P3, ... P10. Out of 10 persons, 5 persons are to be arranged in a line such that in each arrangement P1 must occur whereas P4 and P5 do not occur. Find the number of such possible arrangements.
