How many pairs of letters in the word $CHAIRS$ have as many letters between them in the word as in the alphabet?

How many pairs of letters are there in the word $PENCIL$ which have as many letters between them in the word as in the alphabet?

If you pick up from the following alphabet,the sixth and the fourteenth letters from your right and then pick up the fifth and twentieth letters from your left and form a meaningful word,what is the first letter of that word?
$A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z$

Find which one word cannot be made from the letters of the given word.
$QUINTESSENCE$

If the following alphabet series is written in the reverse order,which letter will be fifth to the left of the fourteenth letter from the left?
$A, B, C, D, E, F, G, H, I, J, K, L, M$
$N, O, P, Q, R, S, T, U, V, W, X, Y, Z$

Find which one word cannot be made from the letters of the given word.
$ENDEAVOUR$