Verified Solution • 2025–26 Session
moderate
QJEEM23Mabc4b: JEE Main 2023 Mathematics - Class 11 JEEM23Mabc4b Solution: The total number of six digit numbers, formed using the digits…
The total number of six digit numbers, formed using the digits 4, 5, 9 only and divisible by 6, is ____________.
Step-by-Step Verified Solution
A number will be divisible by 6 iff the digit at the unit place of the number is divisible by 2 and sum of all digits of the number is divisible by 3 .
Units, place must be occupied by 4 and hence, at least one 4 must be there.
Possible combination of 4, 5, 9 are as follows :
Total = 5 + 5 + 30 + 10 + 10 + 20 + 1 = 81.
Units, place must be occupied by 4 and hence, at least one 4 must be there.
Possible combination of 4, 5, 9 are as follows :
| 4 | 5 | 9 | Total number of Number |
|---|---|---|---|
| 1 | 1 | 4 | |
| 1 | 4 | 1 | |
| 2 | 2 | 2 | |
| 3 | 0 | 3 | |
| 3 | 3 | 0 | |
| 4 | 1 | 1 | |
| 6 | 0 | 0 |
Total = 5 + 5 + 30 + 10 + 10 + 20 + 1 = 81.