Look at the letter sequence below and answer the following question. (Left) S W A Q D F I C X Z O T B H G U K Y M R E (Right) How many letters in the English alphabetical order are there between the fourth letter from the right end of the given series and the fourth letter from the left end of the series?

This question is based on the following words: LAD NOR NEB NOD How many letters are there between the second letter of the second word from the right and the second letter of the second word from the left, counted in English alphabetical order?

This question is based on the following words: RAW MEN AID FAY In each of the words, each vowel is changed to the letter immediately preceding it in the English alphabetical order and each consonant is changed to the letter immediately following it in the English alphabetical order. In how many letter-clusters thus formed will no vowel appear?