The given word is MATHS
Arranging the letters alphabetically, we get
AHMST
When the word starts with any of the letters A/H/M/S, the number of possibilities=4!×4=96
Now when the word starts with TA, then the number of possibilities=3!=6
Now when the word starts with THAMS, then the number of possibilities =1
Rank =96+6+1=103
Hence, rank of the work THAMS is 103.