How many meaningful words can be made from the letters $AEHT$,using each letter only once?

How many pairs of letters are there in the word $FOREIGN$,each of which has as many letters between them as there are between them in the English alphabet?

Arrange the given names in the order in which they would occur in a telephone directory and choose the one that comes in the middle.

How many three-letter meaningful words can be formed from the letters of the word $TEAR$ beginning with $A$ without repeating any letter within that word?

$A$ group of letters is given which are numbered $1, 2, 3, 4, 5$. Below are given four alternatives containing combinations of these numbers. Select the combination of numbers so that the letters arranged accordingly form a meaningful word.
$T, R, I, F, U$
$1, 2, 3, 4, 5$

If each vowel of the word $WEBPAGE$ is substituted with the next letter of the English alphabet,and each consonant is substituted with the letter preceding it,which of the following letters will appear thrice?