Q65.The sum ∑10r=1(r2 + 1) × (r!), is equal to: (1) 11 × (11!) (2) 10 × (11! ) (3) (11)! (4) 101 × (10!) 1
What This Question Tests
Tests the ability to recognize and transform an expression involving factorials into a telescoping series, allowing for efficient calculation of the sum.
Concepts Tested
Formulas Used
r.r! = (r+1)! - r!
Manipulation of algebraic expressions
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📋 Question Details
- Chapter
- Sequences & Series
- Topic
- Special series (telescoping sums)
- Year
- 2016
- Shift
- 10 Apr Online
- Q Number
- Q65
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 9: Sequences and Series
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