A four-digit integer is formed out of 0, 1, 2 and 3 (the same number could be used by more than once) where the sum of all the digits is 3. How many integers in total meet the requirement?
A four-digit integer is formed out of 0, 1, 2 and 3 (the same number could be used by more than once) where the sum of all the digits is 3. How many integers in total meet the requirement?