Permutations And Combinations Question 272

Question: Numbers greater than 1000 but not greater than 4000 which can be formed with the digits 0, 1, 2, 3, 4 (repetition of digits is allowed), are [IIT 1976; AIEEE 2002]

Options:

A) 350

B) 375

C) 450

D) 576

Show Answer

Answer:

Correct Answer: B

Solution:

  • Numbers greater than 1000 and less than or equal to 4000 will be of 4 digits and will have either 1 (except 1000) or 2 or 3 in the first place with 0 in each of remaining places. After fixing $ 1^{st} $ place, the second place can be filled by any of the 5 numbers. Similarly third place can be filled up in 5 ways and $ 4^{th} $ place can be filled up in 5 ways. Thus there will be $ 5\times 5\times 5=125 $ ways in which 1 will be in first place but this includes 1000 also hence there will be 124 numbers having 1 in the first place. Similarly 125 for each 2 or 3. One number will be in which 4 in the first place and $ i.e. $ 4000. Hence the required numbers are $ 124+125+125+1=375 $ ways.



sathee Ask SATHEE

Welcome to SATHEE !
Select from 'Menu' to explore our services, or ask SATHEE to get started. Let's embark on this journey of growth together! 🌐📚🚀🎓

I'm relatively new and can sometimes make mistakes.
If you notice any error, such as an incorrect solution, please use the thumbs down icon to aid my learning.
To begin your journey now, click on

Please select your preferred language
कृपया अपनी पसंदीदा भाषा चुनें