Permutation and Combination Questions

Multiple choice
  1. Quantity II > Quantity I

  2. Quantity I ≥ Quantity II

  3. Quantity I > Quantity II

  4. Quantity I ≤ Quantity II

  5. Quantity I = Quantity II

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Quantity I: Count 7-digit numbers > 3,000,000 from digits {4,2,3,0,3,4,5}. If first digit is 4 or 5: 2 × 720/2 = 720. If first digit is 3: remaining digits {2,0,3,4,4,5} arranged in 720/2 = 360 ways. Total = 1080. Quantity II: In CORRESPONDING, consonants CRRSPNDNG (9 letters, R repeated) must stay together. Treat consonant block + 4 vowels = 5 units. Vowels OEOI (4 distinct) arrange in 4! = 24. Within block, CRRSPNDNG has 9!/2! = 181440 arrangements. Total = 24 × 181440 = 4354560. Since 4354560 > 1080, Quantity II > Quantity I is correct.

Multiple choice
  1. 5120

  2. 2060

  3. 720

  4. 1080

  5. None of these इनमें से कोई नहीं

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

ENTRANCE has 8 letters with vowels E, A, E (E repeats twice). Treat vowels as one block with consonants N, T, R, N, C. Total 6 units can be arranged in 6! ways. Vowels within their block: 3!/2! = 3 ways. Consonants: 5!/2! = 60 ways. Total = 6 × 60 × 3 = 1080.

Multiple choice
  1. 120180

  2. 120216

  3. 120320

  4. 120240

  5. None of these इनमें से कोई नहीं

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Treating vowels (A, E, A, I) as one unit gives 8 units total. These 8 units can be arranged in 8! = 40320 ways. Within the vowel unit, the 4 vowels with A repeated twice can be arranged in 4!/2! = 12 ways. Total arrangements = 40320 × 12 = 483,840. Since none of the given options (120180, 120216, 120320, 120240) match this result, option E is correct.

Multiple choice
  1. 524

  2. 576

  3. 625

  4. 2880

  5. None of these इनमे से कोई नही

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The word OUTSIDE has 6 letters with vowels O, U, I, E (4 vowels) and consonants T, S, D (3 consonants). Treat the 4 vowels as one unit. So we have 4 units total (vowel block + 3 consonants) that can be arranged in 4! = 24 ways. Within the vowel block, the 4 vowels can be arranged in 4! = 24 ways. Total arrangements = 24 × 24 = 576.

Multiple choice
  1. 2, 5, 4, 3, 1

  2. 2, 4, 5, 3, 1

  3. 2, 5, 1, 4, 3

  4. 2, 1, 3, 4, 5

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Arrange the words alphabetically: Palindrome (P-a), Parking (P-a), Pathetic (P-a), Probability (P-r), Protest (P-r). Comparing Parking vs Pathetic: P-a-r-k vs P-a-t-h. 'r' comes before 't', so Parking comes before Pathetic. The order is: 2. Palindrome, 5. Parking, 4. Pathetic, 3. Probability, 1. Protest. This gives the sequence: 2, 5, 4, 3, 1.

Multiple choice
  1. 362880

  2. 120960

  3. 90720

  4. 60480

  5. None of these इनमें से कोई नही

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The word CONSTRUCT has 9 letters with C and T each repeating twice. Number of arrangements = 9! / (2! × 2!) = 362880 / 4 = 90720. We divide by 2! for each repeated letter to account for indistinguishable arrangements. Option C matches this result.

Multiple choice
  1. 720

  2. 360

  3. 120

  4. 650

  5. 2520

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The word INHALE has 6 distinct letters. The number of arrangements is 6! = 6 × 5 × 4 × 3 × 2 × 1 = 720. All letters are different, so no repetition adjustment needed.

Multiple choice
  1. $\dfrac{1}{70}$
  2. $\dfrac{2}{35}$
  3. $\dfrac{1}{35}$
  4. $\dfrac{4}{35}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

ORIENTAL: 8 letters, 4 vowels (O, I, E, A), 4 consonants (R, N, T, L). Total arrangements = 8!. Favorable: V C V C V C V C or C V C V C V C V. 2 * (4! * 4!) = 2 * 24 * 24 = 1152. Total = 40320. Probability = 1152/40320 = 1/35.

Multiple choice
  1. $\displaystyle \frac{3}{5}$
  2. $\displaystyle \frac{2}{5}$
  3. $\displaystyle \frac{1}{5}$
  4. $\displaystyle \frac{4}{5}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The word UNIVERSITY has 10 letters with two I's. Treating the two I's as a single unit, we arrange 9 units in 9!/2! ways (since there are two I's, but we treat them as one block, wait: the letters are U, N, I, V, E, R, S, I, T, Y. There are 10 letters, two I's. Total arrangements = 10!/2!. Arrangements with I's together = 9! ways. Probability = 9! / (10!/2!) = 2/10 = 1/5.