Browse · MATH Print → jmc number theory senior Problem Let n be a positive integer. If a≡(32n+4)−1(mod9), what is the remainder when a is divided by 9? Solution — click to reveal We have that a≡(32n+4)−1≡(9n+4)−1≡4−1≡7(mod9). Final answer 7 ← Previous problem Next problem →