Question

least remainder when 17^30 is divided by 5 is​

Answer 1

Answer:

1730 = (172)15 = (289)15 = (290 – 1)15 ∴ 1730 = 15c0 (290)15 – 15c1 (290)14 + ----- 15c15 (– 1)15 = (multiple of 5) – 1 = 5λ – 1 = 5λ – 5 + 4 = 5(λ – 1) + 4 hence least positive remainder is 4