How many 4-digit numbers can be formed from the digits 1, 3, 4, 5, 6 and 7 , if repetition of the digit is not allowed?…

Share

Q-How many four-digit numbers can be formed from the digits 1, 3, 4, 5, 6 and 7, if repetition of the digit is not allowed?… and if the numbers are greater than 5,000?

Solution

We have 6 digits available.

Related  show that the sequence defined by sn=(1/n+1)+(1/n+2)+(1/n+3)+...+(1/n+n) converges

There are 3 ways to fill the first digit (5,6,7)

5 ways to fill the second digit

4 ways to fill the third digit

3 ways to fill the fourth digit

3×5×4×3=180

180, four-digit numbers if the numbers are greater than 5,000 can be formed from the digits 1, 3, 4, 5, 6 and 7 where the digits are used repetition is not allowed

Q-2 How many 3 digits numbers can be formed from the digits 1,2,3,4,5 and 6 if repetition of the digit is allowed and if repetition of the digit is not allowed?

The first digit can be selected in six ways; and another digit can also be selected in six ways

Related  Evaluating π and e with infinite series | Approximations of π | Approximations of e | pi infinite series

Including the third digit increases the number of ways to

36 \times 6=  216.

Note: If repetition is not allowed, the number of ways will be

 6 \times 5 \times 4 = 120

Q3- How many numbers can be formed from 1, 2, 3, 4, 5 if repetition of the digit is not allowed

Single digit5= \;5\;ways
Two digit5\times4=\;20\; ways
three digit5\times4\times 3= \;60\; ways
four digit5\times4\times 3\times2 =\;120\; ways
five digits5\times4\times 3\times2\times1= \;120\; ways

the number of total numbers = 5 + 20 + 60 + 120 + 120=325


Share

Leave a Reply

Your email address will not be published. Required fields are marked *

Top 5 Most Expensive Domains Ever Sold 4 Must-Try ChatGPT Alternatives: Perplexity AI, BardAI, Pi, and More! Types of Trading Techniques in the Stock Market. ChatGPT app now available in India this AI chatbot can help you make your life more productive. What is wrong with following function code?