find-unit-digit-of-1-2-3-4-5-100-

Question Number 117007 by TANMAY PANACEA last updated on 08/Oct/20

f i n d u n i t d i g i t o f

1! + 2! + 3! + 4! + 5! + \dots . + 100!

Answered by mindispower last updated on 08/Oct/20

i f n ⩾ 5 n! = 0 (10)

1 + 2! + 3! + 4! = 24 + 6 + 4 + 1 = 35

u n i t e 5

Commented by TANMAY PANACEA last updated on 08/Oct/20

i t i s a t r i c k y q u s t e t i o n w h o f a c e i t f i r s t t i m e

Commented by bemath last updated on 09/Oct/20

why not 24 + 6 + 2 + 1 = 33 ?

unit digit 3

Commented by malwaan last updated on 09/Oct/20

u n i t d i g i t i s 3

Commented by TANMAY PANACEA last updated on 09/Oct/20

y e s