Question

a five digit number is formed using digits 1,3,5,7 and 9 without repeating any one of them.What is the sum of all such possible numbers?

Answer 1

Answer:

Step-by-step explanation:

So we know each of our 5 values will appear in each position 24 times. This means that we can sum them up like this:

Sum of ten thousands digits: 24*10,000*(1 + 3 + 5 + 7 + 9)

+

Sum of thousands digits: 24*1,000*(1 + 3 + 5 + 7 + 9)

+

Sum of hundreds digits: 24*100*(1 + 3 + 5 + 7 + 9)

+

Sum of tens digits: 24*10*(1 + 3 + 5 + 7 + 9)

+

Sum of units digits: 24*1*(1 + 3 + 5 + 7 + 9)

= 6,666,600