These three ratio's are equivalent because if you reduce them to simplest form the answer will be 3:1. You multiply each number in the ratio by how many batches you want so for instance 3×2=6 and 1×2=2 so this gives you your first ratio for the 2 batches and 3×4=12 and 1×4=4 this gives you the ration for 4 batches.
