Q. 365.0( 1 Vote )
The number of 5-digit telephone numbers having atleast one of their digits repeated is
A. 90,000
B. 10,000
C. 30,240
D. 69,760
Answer :
Formula:- (i)nPr=
Total of of 5-digit telephone numbers=
If no number is repeated=10P5
The number of 5-digit telephone numbers having atleast one of their digits repeated is
=105-10P5
Rate this question :
Challenging Quiz on P&C | Test Yourself55 mins
Permutations & Combinations | Analyze your learningFREE Class
Understand Permutations like never before60 mins
Check Your progress Part 2| Interactive Quiz: Permutation & Combination54 mins
Lecture on Combinations49 mins
Interactive Quiz on Division and distribution of objects17 mins
Lets see how good you can manage numbers | P&C Quiz Challenge41 mins
Ladoo Bhikhari Concept46 mins
Indepth Understanding of Factorials56 mins
Check Your progress Part 3| Interactive Quiz: Permutation & Combination51 mins
Four letters E, K, S and V, one in each, were purchased from a plastic warehouse. How many ordered pairs of letters, to be used as initials, can be formed from them?
RD Sharma - MathematicsHow many permutations can be formed by the letters of the word, ‘VOWELS,’ when
all vowels come together?
RD Sharma - MathematicsFind the total number of ways in which six ‘+’ and four ‘-‘ signs can be arranged in a line such that no two ‘-‘ signs occur together.
RD Sharma - MathematicsIn how many ways can the letters of the word “INTERMEDIATE” be arranged so that :
i. the vowels always occupy even places?
ii. the relative order of vowels and consonants do not alter?
RD Sharma - MathematicsFrom among the 36 teachers in a school, one principal and one vice-principal are to be appointed. In how many ways can this be done?
RD Sharma - MathematicsHow many different words can be formed with the letters of word ‘SUNDAY’? How many of the words begin with N? How many begin with N and end in Y?
RD Sharma - MathematicsHow many three-digit numbers are there, with distinct digits, with each digit odd?
RD Sharma - MathematicsIn how many ways can five children stand in a queue?
RD Sharma - MathematicsHow many three-digit numbers are there, with no digit repeated?
RD Sharma - Mathematics