Question

Jika hari ini adalah hari selasa,maka 5 pangkat 2000 lagi hari apa?????

Answer 1

(5^2000) mod7
= (5^2)^1000 mod7
= (25^1000) mod7
= (21+4)^1000 mod7
= (4^1000) mod7
= (2^2000) mod7
= (2^(3x666+2)) mod7
= (2^2) mod7 * (8^666) mod(7)
= (4) mod7 * (7+1)^666 mod7
= (4) mod7 * (1) mod7
= (4 * 1) mod7
= (4) mod7
so, 4 hari setelah hari selasa = sabtu