This question is based on the following words: (Left) FRY AUK GEM GUN (Right) 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?

If 1 is added to each odd digit and 2 is subtracted from each even digit in the number 6581734, what will be the sum of the digits which are second from the left and second from the right?

Each vowel in the word ENGLISH is changed to the letter immediately following it in the English alphabetical order and each consonant is changed to the letter immediately preceding it in the English alphabetical order. Which of the following letters will appear exactly twice in the group of letters thus formed?