Advertisements
Advertisements
Question
Choose the correct alternative:
If Pr stands for rPr then the sum of the series 1 + P1 + 2P2 + 3P3 + · · · + nPn is
Options
Pn + 1
Pn + 1 – 1
Pn + 1 + 1
`""^(("n" + 1))"P"_(("n" - 1))`
Advertisements
Solution
Pn + 1
APPEARS IN
RELATED QUESTIONS
if `1/(6!) + 1/(7!) = x/(8!)`, find x
In how many ways can the letters of the word ASSASSINATION be arranged so that all the S’s are together?
How many natural numbers not exceeding 4321 can be formed with the digits 1, 2, 3 and 4, if the digits can repeat?
Three dice are rolled. Find the number of possible outcomes in which at least one die shows 5 ?
In how many ways can 7 letters be posted in 4 letter boxes?
Write the total number of possible outcomes in a throw of 3 dice in which at least one of the dice shows an even number.
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?
In how many ways 5 boys and 3 girls can be seated in a row, so that no two girls are together?
Evaluate the following.
`(3! + 1!)/(2^2!)`
Three men have 4 coats, 5 waist coats and 6 caps. In how many ways can they wear them?
A student appears in an objective test which contain 5 multiple choice questions. Each question has four choices out of which one correct answer.
How will the answer change if each question may have more than one correct answers?
In how many ways can the letters of the word SUCCESS be arranged so that all Ss are together?
How many strings are there using the letters of the word INTERMEDIATE, if the vowels and consonants are alternative
How many strings are there using the letters of the word INTERMEDIATE, if all the vowels are together
Suppose m men and n women are to be seated in a row so that no two women sit together. If m > n, show that the number of ways in which they can be seated is `(m!(m + 1)!)/((m - n + 1)1)`
The number of different words that can be formed from the letters of the word INTERMEDIATE such that two vowels never come together is ______.
The number of three-digit even numbers, formed by the digits 0, 1, 3, 4, 6, 7 if the repetition of digits is not allowed, is ______.
If the letters of the word 'MOTHER' be permuted and all the words so formed (with or without meaning) be listed as in a dictionary, then the position of the word 'MOTHER' is ______.
