Advertisements
Advertisements
प्रश्न
The number of permutation of n different things taken r at a time, when the repetition is allowed is ______.
विकल्प
rn
nr
`(n!)/((n - r)!)`
`(n!)/((n + r)!)`
Advertisements
उत्तर
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
संबंधित प्रश्न
A coin is tossed three times and the outcomes are recorded. How many possible outcomes are there? How many possible outcomes if the coin is tossed four times? Five times? n times?
In how many ways 4 women draw water from 4 taps, if no tap remains unused?
The product of r consecutive positive integers is divisible by
In a room there are 12 bulbs of the same wattage, each having a separate switch. The number of ways to light the room with different amounts of illumination is
English alphabet has 11 symmetric letters that appear same when looked at in a mirror. These letters are A, H, I, M, O, T, U, V, W, X and Y. How many symmetric three letters passwords can be formed using these letters?
Evaluate the following.
`(3! + 1!)/(2^2!)`
The greatest positive integer which divide n(n + 1) (n + 2) (n + 3) for all n ∈ N is:
Three men have 4 coats, 5 waist coats and 6 caps. In how many ways can they wear them?
Choose the correct alternative:
The product of r consecutive positive integers is divisible b
The number of 5-digit telephone numbers having atleast one of their digits repeated is ______.
