Class 11MathematicsPermutation and CombinationDefinition of permutation, Number of permutations with or without repetition, Conditional permutations
EasyIf $0 < r < s < n$ and ${}^n P_r = {}^n P_s$,then find the value of $r + s$.
- A$2n - 2$
- B$2n - 1$
- C$2$
- D$1$
Explore More
Similar Questions
How many arrangements can be made using the letters of the word $CALCUTTA$?
Easy
View SolutionHow many different nine-digit numbers can be formed from the digits of the number $223355888$ by rearranging the digits such that the odd digits occupy even places?
MediumIIT 2000
View SolutionThere are $4$ parcels and $5$ post-offices. In how many different ways can the registration of the parcels be made?
Easy
View SolutionIf the letters of the word $SACHIN$ are arranged in all possible ways and these words are listed in dictionary order,what is the rank of the word $SACHIN$?
Difficult
View SolutionIf $^{56}P_{r + 6} : ^{54}P_{r + 3} = 30800 : 1$,then $r = $
Medium
View SolutionVedclass Products
For Students
Vedclass Test Series
Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.
Start Free TrialFor Teachers
Exam Paper Generator
Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.
Try FreeFor Institutes
Online Exam Module
Live online exams with unlimited students, 360° analytics & white-label branding.
See Demo