This is 30% of the apples in the barrel. How many apples are in the entire barrel?
To solve this question, we need to remember that 100% represents the "whole" or "the entire thing". In this problem, we do not know how many apples represent 100%, but we do know that 6 apples are equal to 30%. 
There are many ways to solve the above problem. Here are a few of them:
Method 1  Method 2  Method 3 
Since 6 apples equals 30%, each apple is 5%. 5 x 20 = 100, so there are 20 apples. 
NOTE: This proportion was set up by putting 6 and 30% on top, since 6 apples equals 30%. 
All three methods will lead to the same answer  there are 20 apples in the entire barrel.
Example 2
Jennifer scored 12 points for her basketball team. If this was 40% of the total points scored, how many points did her team score altogether?
Method 1  Method 2  Method 3  Method 4 
12 points can be broken into four groups of 3. This means every 3 points is equal to 10%. 
Using a table, we can scale the ratio of 12 to 40 up and down. Eventually, we can add 80% and 20% to find the number of points in 100%. 
This proportion follows the format of $\frac{part}{whole}=\frac{part}{whole}$ . 12 points and 40% are the "parts", so they go on top. 
Since 40% can be partially reduced to $\frac{12}{30}$, this shows that there were 30 points scored altogether.

Question 1 This is 60% of the band. How many musicians are in the whole band?

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Question 2 These are 8% of the cars in the parking lot. How many cars are in the parking lot?

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Question 3 This is 40% of the birds in the cage. How many birds are in the cage?

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