Step-by-step explanation:
2112 + 2212 + 2312 / 4 leaves no remainder, as already the individual numbers could be divided by 4 without remainder.
2113 = 2112 + 1
2213 = 2212 + 1
so, we get a remainder of +1 and +1 for these 2 numbers, so we get in total a remainder of +2.
