Advertisements
Advertisements
प्रश्न
How many numbers lesser than 1000 can be formed using the digits 5, 6, 7, 8, and 9 if no digit is repeated?
Advertisements
उत्तर
The required numbers are lesser than 1000.
They are one digit, two-digit or three-digit numbers.
There are five numbers to be used without repetition.
One digit number: One-digit numbers are 5.
Two-digit number: 10th place can be filled by anyone of the digits by 5 ways and 1’s place can be 4 filled by any of the remaining four digits in 4 ways.
∴ Two-digit number are 5 × 4 = 20.
Three-digit number: 100th place can be filled by any of the 5 digits, 10th place can be filled by 4 digits and one’s place can be filled by 3 digits.
∴ Three digit numbers are = 5 × 4 × 3 = 60
∴ Total numbers = 5 + 20 + 60 = 85.
APPEARS IN
संबंधित प्रश्न
From a committee of 8 persons, in how many ways can we choose a chairman and a vice chairman assuming one person cannot hold more than one position?
Find the number of ways in which 8 distinct toys can be distributed among 5 childrens.
Write the number of arrangements of the letters of the word BANANA in which two N's come together.
Write the number of ways in which 6 men and 5 women can dine at a round table if no two women sit together ?
Evaluate the following.
`(3! + 1!)/(2^2!)`
Determine the number of permutations of the letters of the word SIMPLE if all are taken at a time?
8 women and 6 men are standing in a line. In how many arrangements will all 6 men be standing next to one another?
Find the distinct permutations of the letters of the word MISSISSIPPI?
How many strings are there using the letters of the word INTERMEDIATE, if all the vowels are together
Let b1, b2, b3, b4 be a 4-element permutation with bi ∈ {1, 2, 3, .......,100} for 1 ≤ i ≤ 4 and bi ≠ bj for i ≠ j, such that either b1, b2, b3 are consecutive integers or b2, b3, b4 are consecutive integers. Then the number of such permutations b1, b2, b3, b4 is equal to ______.
