Solution:ACCUMUATES
the 1st letter is interchanged with the 2nd, we get, CACUMUATES
After 3rd letter with the 4th, we get CAUCMUATES
After 5th with the 6th, CAUCUMATES
After 7th with the 8th CAUCUMTAES
And after 9th with the 10th, CAUCUMTASE
then the 6th letter from the left will be: M