Serlea-Shows-that-the-sum-of-the-digit-of-100-25-25-is-divisible-by-4-

Question Number 85184 by Serlea last updated on 19/Mar/20

Serlea

Shows that the sum of the digit of

100^{25} - 25

is divisible by 4 .

Commented by mr W last updated on 19/Mar/20

100^{25} = 10^{50} = 1 \underset{50 z e r o s}{00 \dots 000}

100^{25} - 25 = 1 \underset{50 z e r o s}{00 \dots 000} - 25 = \underset{48 9 s}{99 . . 975}

s u m o f d i g i t s = 48 \times 9 + 7 + 5 = 444 = 111 \times 4

w h i c h i s d i v i s i b l e b y 4 .

Commented by Serlea last updated on 26/Mar/20

Great

Facebook Tweet Pin