If the first half of the English alphabet series (from A to M) is written in reverse order, which letter will be the seventh to the right of the fifteenth letter from the left end?

The position(s) of how many letters will remain unchanged if each of the letters in the word WALKOVER is arranged in English alphabetical order?

The letters of the word JETFOILS are arranged in alphabetical order. How many letters will be there in the English alphabetical series between the second letter from the left and the third letter from the right in this newly formed letter group?