GMAS 6th Grade Mathematics Practice Test

Equivalent ratios express the same value between the two parts. You can see this by simplifying. For 6:8, dividing top and bottom by 2 gives 3:4, so it matches 3:4. The same idea holds for 9:12, which simplifies to 3:4 as well. The ratio 3:4 is already in simplest form and represents that same value. The ratio 5:6 equals 5/6, which is not the same as 3/4, so it isn’t equivalent.