Each letter in the word GUILDER is arranged in the English alphabetical order. How many letters are there in the English alphabetical order between the letter which is fourth from the left end and the one which is first from the right end in the new letter-cluster thus formed?​​​

Given: GUILDER

Letters in "GUILDER":

G, U, I, L, D, E, R

Arranged in alphabetical order:
D, E, G, I, L, R, U

Fourth from the left → I

First from the right → U

Now we find the letters come between I and U in the English alphabet.

J, K, L, M, N, O, P, Q, R, S, T

So, 11 letters between them.