Each vowel of the GLADIOLUS word is substituted with the next letter of the English alphabetical series and each consonant is substituted with the letters preceding it. How many vowels will be present in the new arrangement?

Explanation:-

G → F
L → K
A → B
D → C
I → J
O → P
L → K
U → V
S → R
Thus,
GLADIOLUS = FKBCJPKVR.