Question

How many numbers lying between 1000 and 10000 can be formed by using the digits 1,3,5,6,7,8,9 no digits being repeated?

Answer 1

This is the requested number: ABCD As ABC is greater than 400 and less than 1000, we conclude that: 1. A can be one of 4, 5, 6.

Answer 2

Answer:

Total numbers which can be formed = 840

Step-by-step explanation:

We need to find the no. of numbers formed by using the digits 1, 3, 5, 6, 7, 8, 9 and the numbers must lie between 1000 and 10000

Now, the numbers which lie between 1000 and 10000 are actually all 4 digits numbers

So, we need to find all 4 digit numbers that can be formed by using the given digits : 1, 3, 5, 6, 7, 8, 9

Therefore, The required numbers which can  be formed without repetition of the digits :

No. of digits = 7

Number of possibilities = 4

So, Total numbers which can be formed = 7 × 6 × 5 × 4

                                                                      = 840