To find: number of 6 digit
0 cannot be in the first place because that would make a 5 - digit number
Total number of 6 - digit numbers = Total number of number possible - Number of numbers with 0 at the first place
Total number of numbers possible = \(\frac{6!}{2!2!}\) = 180
Number of numbers with 0 at first place = \(\frac{5!}{2!2!}\) = 30
⇒ Number of 6 - digit numbers = 180 - 30 = 150
150 six - digit numbers are possible
