Maths Olympiad Prep

Track / Stage 4 / 99 of 340 #359 of 1964

Problem 359

AMC 12 late, AIME early
Number theory Difficulty 4.7 Find the answer

2.420×814×16162.420 \times 814 \times 1616 divided by 13 has a remainder of

A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.

Official solution

【Analysis】 420×814×16164×8×412811(mod13)420 \times 814 \times 1616 \equiv 4 \times 8 \times 4 \equiv 128 \equiv 11(\bmod 13)

Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic, difficulty and ordering added by this site.