What would be the sum of all 3 digit number formed by using digits 3, 4, 6 & 8, with no digit is

What would be the sum of all 3 digit number formed by using digits 3, 4, 6 & 8, with no digit is




Solution -

Nevertheless I have used a spread sheet to find the 4P3 i.e. 24 three digit numbers. Each column has any digit 6 times. Hence the total of any column is 6*(3+4+6+8) i.e. 126. Writing 6 in the unit place we carry 12 to the second column which again has a total of 126 which makes it 126+12=138. We write 8 in the tens place and carry 13 to the third column. The third column will be 126+13=139 which we have to write as it is. Hence the answer reads 13986.