Place each of the digits 0 through 9, without repetition, in the boxes

\(□+□□+□□□+□□□□\)

Place each of the digits 0 through 9, without repetition, in the boxes above. What is the maximum possible sum?

(Assumption: \(□□\) would represent the 2-digit number)

To maximise the sum, we have to assign lower place value to smaller digits and higher place value to bigger digits.
Unit digits = 4
Tens digits = 3
Hundredth digits = 2
Thousandth digit = 1

Therefore, 0,1,2,3 will occupy unit digits, 4,5 & 6 will occupy tens digits, 7 & 8 will occupy hundredth digit and 9 will occupy thousandth digit.

Maximum sum = (0+1+2+3) + 10(4+5+6) + 100(7+8) + 1000*9 = 6 + 150 + 1500 + 9000 = 10656
e.g. Maximum possible sum = 1 + 40 + 752 + 9863 = 10656

IMO C