Each of the digits, 1, 1, 2, 3, 3, 4, 6 is written on a separate card. The seven cards are then laid out in a row to form a 7-digit number.
(a) how many distinct 7-digit numbers are there? [answered - might be related, so posting here]
7! / 2!x2! = 1260
(d) How many of these 7-digit numbers start and end with the same digit?
Do we need to consider distinct objects in this question? I don't get it. I have tried different ways but all failed.