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

So, the question essentially asks to find out pairs of letters in the given word "NURSING" which have same number of letter between them as there are in english alphabet. We can start with the first letter initially and then try to check for subsequent letters. Lets take N, now NU have 6 letter between them in english alphabets, here they don't have any letter so this cannot be a possible pair. Lets move on to NR again NR have just 1 letter between them which is not the case in actual english alphabets. Proceeding in a similar manner we can find that words fulfilling the given requirement are

US, RS, IG Thus there are just 3 pairs of words meeting such requirement.