Question 25
Using 5 nonzero digits, we can form 120 numbers without repeating a digit in a number. Let $S$ be the sum of all these numbers. Find the sum of the digits of $S$ when:
a) The five digits are 1, 3, 5, 7, and 9;
b) The five digits are 0, 2, 4, 6, and 8. Recall that 02468 is a four-digit number, so in this case there will not be 120 numbers.
a) The five digits are 1, 3, 5, 7, and 9;
b) The five digits are 0, 2, 4, 6, and 8. Recall that 02468 is a four-digit number, so in this case there will not be 120 numbers.