COMEDK · Maths · 36. Probability
The probability of inviting three friends on 5 consecutive days, exactly one friend a day and no friend is invited on more than two days is
- A \(\dfrac{10}{81}\)
- B \(\dfrac{20}{81}\)
- C \(\dfrac{10}{27}\)
- D \(\dfrac{5}{27}\)
Answer & Solution
Correct Answer
(C) \(\dfrac{10}{27}\)
Step-by-step Solution
Detailed explanation
There are 3 friends and 5 days. Each day, one friend is invited, so there are \(3^5 = 243\) total ways to invite friends. Let the friends be \(A, B, C\). We need to count the number of ways such that each friend is invited at most twice. Since there are 5 days, the possible…
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