Number TheoryHardModular Arithmetic ShareModular Arithmetic · Hard problemEvaluate 1⋅2+2⋅3+3⋅4+⋯+99⋅1001\cdot2 + 2\cdot3 + 3\cdot4 + \cdots + 99\cdot1001⋅2+2⋅3+3⋅4+⋯+99⋅100 modulo 999 (as a residue from 000 to 888).Check Show answer Walk through it step by step Practice more like this Review this concept