Question 1
How many arrangements of the letters in 'EQUATION' start with a vowel?
Step-by-Step Solution:
Concept: Permutation with restriction - specific position must have certain type of letter.
Strategy: Fix the restricted position first, then arrange the remaining letters.
Analysis of 'EQUATION':
- Total letters: 8
- Vowels: E, U, A, I, O = 5 vowels
- First position must be a vowel
Step 1 - Fix First Position:
Choose a vowel for first position: 5 choices
Step 2 - Arrange Remaining:
Remaining 7 letters can be arranged in 7! ways
7! = 5040
Calculation:
Total arrangements = 5 × 5040 = 10080
Key Strategy: When dealing with restrictions:
1. Handle the restriction first (fix the constrained position)
2. Arrange the remaining elements freely
3. Multiply the results
Verification: This should be less than the total arrangements (8! = 40320) since we've added a constraint.
Concept: Permutation with restriction - specific position must have certain type of letter.
Strategy: Fix the restricted position first, then arrange the remaining letters.
Analysis of 'EQUATION':
- Total letters: 8
- Vowels: E, U, A, I, O = 5 vowels
- First position must be a vowel
Step 1 - Fix First Position:
Choose a vowel for first position: 5 choices
Step 2 - Arrange Remaining:
Remaining 7 letters can be arranged in 7! ways
7! = 5040
Calculation:
Total arrangements = 5 × 5040 = 10080
Key Strategy: When dealing with restrictions:
1. Handle the restriction first (fix the constrained position)
2. Arrange the remaining elements freely
3. Multiply the results
Verification: This should be less than the total arrangements (8! = 40320) since we've added a constraint.