Class 11MathematicsPermutation and CombinationDefinition of permutation, Number of permutations with or without repetition, Conditional permutations
EasyWhile dialing a telephone number,an old man forgets the last two digits,remembering only that these are different. If he dials the last two digits at random,what is the probability that the number is dialed correctly?
- A$\frac{1}{45}$
- B$\frac{1}{90}$
- C$\frac{1}{100}$
- DNone of these
Explore More
Similar Questions
In how many ways can $5$ prizes be distributed among four students when every student can take one or more prizes?
Easy
View SolutionIf the number of words,with or without meaning,which can be made using all the letters of the word $MATHEMATICS$ in which $C$ and $S$ do not come together,is $(6 !) k$,then $k$ is equal to $............$.
DifficultJEE MAIN 2023
View SolutionIf all the digits in the number $53426$ are permuted in all possible ways and are arranged in decreasing order,then the number having rank $89$ is:
How many numbers greater than $24000$ can be formed using the digits $1, 2, 3, 4, 5$ without repetition?
Medium
View SolutionFind the number of different $8$-letter arrangements that can be made from the letters of the word $DAUGHTER$ such that all vowels occur together.
Easy
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