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

• since there 5 digits therefore 5*4*3*2*1=120 distinct combinations possible without repetition
  
  each of our 5 values will appear in each position 120/5=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
• 9 years agoHelpfull: Yes(1) No(1)
• are you sure Xperia this ans and method is correct?????i don't or know how to solve this if this is surely correct then plzz rep
• 9 years agoHelpfull: Yes(0) No(0)
• yes, answer is correct just go to below link and scroll down for full explanation
  http://www.urch.com/forums/gre-math/143005-five-digit-number-formed-using-digits-1-3-5-7-9-a.html
• 9 years agoHelpfull: Yes(0) No(0)