7 Nine cards are numbered \(1,2,2,3,3,4,6,6,6\).
- All nine cards are placed in a line, making a 9-digit number. Find how many different 9-digit numbers can be made in this way
(a) if the even digits are all together,
(b) if the first and last digits are both odd. - Three of the nine cards are chosen and placed in a line, making a 3-digit number. Find how many different numbers can be made in this way
(a) if there are no repeated digits,
(b) if the number is between 200 and 300 .