48 / 20 = 12 / 5
4.8 is the ratio 48/10 . You can never write 4.8 as a singlewhole number, simply because 4.8 is not a whole number.
5:11
18 to 25
5 to 10 = 1 to 2
7.2 to 10 = 72 to 100 = 18 to 25
If you mean as a ratio then it is 1/2
3.6 = 36/10. You can simplify that ratio if you like.
The ratio is simply 4:40. You could, if you so wished, simplify it to 1:10.
3 lb:10 oz = 48 oz:10 oz = 48:10 = 24:5
12 : 20 = 6 : 10 = 3 : 5
simplify the ratio 18b^2 to 45b