Arrange ratio:
If the dog ate 12 muffins and this accounted for three-tenths of total how many muffins is a whole? Therefore, our ratio is as follows:
where 1 is a whole, and 3/10 = 0.3
12 ----------- 0.3
x ------------- 1
Multiply on the cross:
12 * 1 = 0.3 * x
0.3x = 12 |:0,3
x = 40
There are 40 muffins.
