The number of 6 digit numbers that can be made with the digits 1,2,3,4

Text Solution

4805401080none of these

Solution : The number of 6-digits has two pairs of digits and 2 different digits. <br> The number of ways of selecting 2 digits for two pairs and 2 other digits `=""^(4)C_(2)xx""^(2)C_(2)`. Now, we arrange these six digits which consists of two pairs and 2 different digits. This can be done in `(6!)/(2!2!)` ways. <br> `:.` Required numbers `=""^(4)C_(2)xx""^(2)C_(2)xx(6!)/(2!2!)=1080`.