angelinararr4479 angelinararr4479 Today at 7:53 AM Mathematics Answered How many ordered pairs of integers (a, b) are needed to guarantee that there are two ordered pairs (a1, b1 ) and (a2, b2 ) such that a1 mod 5 = a2 mod 5 and b1 mod 5 = b2 mod 5? A) Modular Arithmetic B) Number Theory C) Set Theory D) Combinatorics