1/5=6/30 if thats what you mean
10/12 and 3/12 6 x 2=12, what you do to the bottom you do to the top 5 x 2= 10 4 x 3=12, what you to the bottom you do to the top 1 x 3=3
The ratio of length to width would change slightly, before adding on to the dimensions, the ratio is 6 : 2.5 with the added dimensions, the ratio would change to 8 : 4.5 with simple math you can see that 2.5 is less then half of 6 while 4.5 is more then half of 8