Question

Defined N! = N x (N-1) x .. x 2 x 1 and N # = N + (N-1) + ... + 2 + 1
Example: 4! = 4 x 3 x 2 x 1 = 24
4 # = 4 + 3 + 2 + 1 = 10
What is the last digit of ((5 #) #) + ((3 #) #) - ((5!)! + (3!)!)?

Answer 1

@mathmate @FaiqRaees

Answer 2

Well that's a heck of a calculation

Answer 3

Lol

Answer 4

That's the question

Answer 5

Are you allowed to use a calculator?

Answer 6

You need to find the last digit of ((5 #) #) + ((3 #) #) - ((5!)! + (3!)!)

Answer 7

It just about pattern.
We must solve it the easiest way without calculator

Answer 8

! is factorial
# is summation
@FaiqRaees

Answer 9

I am pretty much aware of that

Answer 10

Owhh... I got it

Answer 11

Thx guys and Una :D

Answer 12

:D I love these

Answer 13

@brainzonly lol
I still have many question, don't worry

Answer 14

yay