What is the probability that <strong>ALL</strong> three boys sit together?

Consider the following for the next five (05) items that follow: Three boys P, Q, R and three girls S, T, U are to be arranged in a row for a group photograph.

  1. A. \frac{1}{5}
  2. B. \frac{1}{4}
  3. C. \frac{1}{3}
  4. D. \frac{1}{12}

Correct Answer: A. \frac{1}{5}

Explanation

Total number of arrangements for 6 people is 6! = 720. If 3 boys sit together, they form a single unit. There are now 4 units (the group of boys + 3 individual girls), which can be arranged in 4! = 24 ways. The 3 boys can arrange among themselves in 3! = 6 ways. Total favorable outcomes = 24 \times 6 = 144. The probability is \frac{144}{720} = \frac{1}{5}.

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