What is the value of 1×1!+2×2!+3×3!+............n×n!; where n! means n factorial or n(n-1)(n-2)...1
(n+1)!-1
(n+1)!
n!-1
None of these
n*n! = (n+1-1)*n! = (n+1)! - n!
So ∑n*n! = (n+1)! - 1
The sum of (n+1) terms of 12+11+2+11+2+3+.......... is