10 examination papers arranged such that best and worst are not togeth...
Understanding the Problem
To arrange 10 examination papers such that the best and the worst are not together, we can approach the problem systematically.
Step 1: Total Arrangements
- The total arrangements of 10 papers without any restrictions is given by \(10!\).
- Calculation:
\(10! = 3,628,800\)
Step 2: Arrangements with Restrictions
- To find the arrangements where the best and worst are together, we can treat them as a single unit or block.
Step 3: Treating Best and Worst as a Block
- This block can be arranged in 2 ways (Best-Worst or Worst-Best).
- Now, we have 9 units to arrange (the Best-Worst block + 8 other papers).
- The arrangements of these 9 units is \(9!\).
- Calculation:
\(9! = 362,880\)
Step 4: Total Arrangements with Best and Worst Together
- Total arrangements with Best and Worst together:
\(2 \times 9! = 2 \times 362,880 = 725,760\)
Step 5: Applying the Principle of Inclusion-Exclusion
- To find the arrangements where Best and Worst are NOT together, subtract the arrangements where they are together from the total arrangements:
\[
\text{Arrangements with Best and Worst NOT together} = 10! - (2 \times 9!)
\]
- Calculation:
\(3,628,800 - 725,760 = 2,903,040\)
Final Result
- The number of arrangements of the 10 examination papers such that the best and worst are not together is **2,903,040**.
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