Given digits are 1, 2, 3, 4, 5, 6
To find : number of 3-digit even numbers
Since the required number is even, it has to be end with 2, 4 or 6, therefore unit’s place can be filled in only 3 ways.
Since the repetition of the digits is allowed, therefore hundred’s place and ten’s place can be filled each in 6 ways.
Hence three places can be filled in 6 x 6 x 3 ways i.e., 108 ways.
∴ Required number of numbers = 108