The sum of five digit numbers which can be formed with the digits 3, 4, 5, 6, 7 using each digit only once in each arrangement, is

The number of numbers of five digits, having 3 in unit’s place =4P4 (number of arrangements of the remaining four digits)= 4! = 24.Similar is the case for other digits, i.e., each digit occurs 24 times in the unit’s place.Hence, the sum of the digits in unit’s place=24×3+24×4+24×5+24×6+24×7=24(3+4+5+6+7)=24×25=600Similarly, the sum of the digits in each of the other places = 600.∴ The required sum=600×10000+600×1000+600×100+600×10+600×1 =600(10000+1000+100+10+1) =600×11111=6666600.