In the word ‘ENVIRONMENT’, if all the consonants are replaced with their immediate previous letter and all the vowels are replaced with their immediate next letter according to alphabetical series, then how many vowels are there in the new word formed after the rearrangement?

The correct option is One.

Let's break down the word ENVIRONMENT step-by-step according to the given instructions.

Step 1: Identify each letter in the word 'ENVIRONMENT' as a vowel or a consonant.

The standard English vowels are A, E, I, O, U. All other letters are consonants.

• E: Vowel
• N: Consonant
• V: Consonant
• I: Vowel
• R: Consonant
• O: Vowel
• N: Consonant
• M: Consonant
• E: Vowel
• N: Consonant
• T: Consonant

Step 2: Apply the rearrangement rules to each letter.

Rule 1: Replace all consonants with their immediate previous letter in the alphabetical series.
Rule 2: Replace all vowels with their immediate next letter in the alphabetical series.

Let's transform each letter one by one:

1. E (Vowel) → Immediate next letter = F
2. N (Consonant) → Immediate previous letter = M
3. V (Consonant) → Immediate previous letter = U
4. I (Vowel) → Immediate next letter = J
5. R (Consonant) → Immediate previous letter = Q
6. O (Vowel) → Immediate next letter = P
7. N (Consonant) → Immediate previous letter = M
8. M (Consonant) → Immediate previous letter = L
9. E (Vowel) → Immediate next letter = F
10. N (Consonant) → Immediate previous letter = M
11. T (Consonant) → Immediate previous letter = S

Step 3: Form the new word and count the vowels in it.

The new word formed after replacement is: F M U J Q P M L F M S

Now, let's identify the vowels (A, E, I, O, U) present in the new word:

• F, M are consonants.
• U is a VOWEL.
• J, Q, P, M, L, F, M, S are consonants.

Therefore, there is only One vowel (the letter 'U') in the new word formed.