Which of the following is equivalent to the ratio 3ab: 27ab select all that apply
1: 9
9a: 81a
a: b
a: 3b
2: 18
3b: 27a
there are 3 correct

To determine the equivalent expressions for the given expression which is 3ab:27ab = 1:9 , we can simplify the choices and see whether they are equal with the original.

1:9 = 1:9  EQUAL

9a:81a = 1:9 EQUAL 

a:b NOT EQUAL

a:3b NOT EQUAL

2:18 = 1:9 EQUAL

3b:27a = NOT EQUAL