S=1+2!1+3+3!1+3+5+…=r=1∑∞r!r2=r=1∑∞(r−1)!(r−1+1)=r=2∑∞(r−2)!1+r=1∑∞(r−1)!1=2e
The sum 1+ 1+3 2!+ 1+3+5 3!+ 1+3+5+7 4!+… upto ∞ terms, is equal to
JEE Main 2025 — Mathematics Algebra
The sum 1+2!1+3+3!1+3+5+4!1+3+5+7+… upto ∞ terms, is equal to
Held on 3 Apr 2025 · Verified 6 Jul 2026.
Options
- A
6e
- B
4e
- C
3e
- D
2e
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