The ratio of two numbers a and be is written as a:b. The same can be written as a/b. Example ratio of 3 and 4 is written as 3:4 or 3/4.Proportion means if two ratios are equal then we call it as proportion. For example of a:b = c:d, then we call them as proportion and it will be written as a:b::c:d. And it is said to be a,b,c, and d are in proportion. Example of proportion is 5:15 = 1:3, so it can be written as 5:15::1:3. This section covers all the questions and answers on ration and proportions. ration and proportion is part of arithmetic.