Apparently, this user prefers to keep an air of mystery about them.
16 History of zero? jun 3 '11
2 Permutation and Combination with divisibility? dec 26 '12
2 In how many ways can 5 different toys be packed in 3 identical boxes such that no box is empty, if any of the boxes may hold all of the toys? dec 27 '12
0 mixture and solution problem? apr 1 '14