JEE Mains · Maths · STD 11 - 6. permutation and combination
A building has ground floor and 10 more floors. Nine persons enter in a lift at the ground floor. The lift goes up to the \(10^{\text{th}}\) floor. The number of ways, in which any 4 persons exit at a floor and the remaining 5 persons exit at a different floor, if the lift does not stop at the first and the second floors, is equal to :
- A \(2184\)
- B \(3064\)
- C \(7056\)
- D \(11340\)
Answer & Solution
Correct Answer
(C) \(7056\)
Step-by-step Solution
Detailed explanation
Total number of persons = \(9\) The lift goes up to the \(10^{\text{th}}\) floor but does not stop at the \(1^{\text{st}}\) and \(2^{\text{nd}}\) floors. Thus, the available floors for the persons to exit are from the \(3^{\text{rd}}\) to the \(10^{\text{th}}\) floor. Number of…
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