Question

what is the unit digit of 1!+2!+3!+4!+...+50!​

Answer 1

Step-by-step explanation:

(1) 1! = 1

(2) 2! = 2

(3) 3! = 6

(4) 4! = 24

(5) 5! = 120

From 5!, the unit digit will always be zero. So,

1! + 2! + 3! + 4!

=1 + 2 + 6 + 24

=33

Therefore the unit digit is 3.