Question

How many numbers less than 500 can be formed from the digits 2,3,4,5,6 and 7 of preparation of digits not allowed​

Answer 1

Step-by-step explanation:

4 possible 1st digit : 1, 2, 3, 4 (1st digits greater than 4 will be over 500)

6 possible 2nd digit : any of 1, 2, 3, 4, 5, 6, 7, except the digit we just used.

5 possible 3rd digit : any of 1, 2, 3, 4, 5, 6, 7, except the 2 digits we just used

Finally, we can form 4×6×5=120 numbers