These quotients are different because of what division means.
When you divide you start with a total and break it into equal groups. If you started with three and broke them into groups of 1/5, that is different then starting with 1/5 and breaking into three groups.
If you had 3 cups of Chex mix and made servings of 1/5 of a cup. How many servings could you get? This is 3 divided by 1/5.
If you want to put tomatoes in 1/5 of your garden and you have 3 different tomatoes you want to plant. What fraction of the original garden will each type of tomato be in if they are evenly distributed.