TS EAMCET · Maths · Permutation Combination
If and then Note: Question Corrected
- A
- B
- C
- D
Answer & Solution
Correct Answer
(B)
Step-by-step Solution
Detailed explanation
o<r<s<n Given, Prn=Psn ⇒n!n-r!=n!n-s! ⇒n-r!=n-s! .....i As r≠s, so only possibility for i to hold is n-r=1, n-s=0 ⇒r+s=2n-1
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