MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: R

There are no items in this cart.
Continue Shopping
Menu
monika sinha Grade:
        

Hi ....i have a question from permution and combination.


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


plz reply !!!!!


 






8 years ago

Answers : (1)

raj kaushik
26 Points
										

1*1! = (2 -1)*1! = 2*1! - 1*1! = 2! - 1!



2*2! = (3 - 1)*2! = 3*2! - 2! = 3! - 2!



3*3! = (4 - 1)*3! = 4*3! - 3! = 4! - 3!

..

..

..



n*n! = (n+1 - 1)*n! = (n+1)(n!) - n! = (n+1)! - n!



Summing up all these terms, we get (n+1)! - 1!

8 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies
  • Complete JEE Main/Advanced Course and Test Series
  • OFFERED PRICE: R 15,000
  • View Details
Get extra R 3,000 off
USE CODE: CART20
Get extra R 440 off
USE CODE: CART20

Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details