In typography, "12 over 15" in picas typically indicates a font size of 12 points with a leading (line spacing) of 15 points. This means that the text is set in a size that is 12 points tall, and the space between the baselines of successive lines of text is 15 points. The additional space allows for better readability and can affect the overall appearance of the text layout.
15/12
12 over 15.
12/15 = 0.8
It is 15/12
12/15 + 5/12 = 73/60 or 113/60
3/16 x 15/12 is 15/64
2/3 minus 12/15 is -2/15
4/12 + 11/15 = 1 1/15
7/12+8/12 = 15/12 15/12 = 5/4 or 1.25
12/15 equals 0.8
12/15 = 4/5
The ratio of 15 over 12 is 5:4.