An advertisement for a pineapple drink claims that the drink contains 15%pineapple juice. How much pure pineapple juice would have to be added to 8 quarts of the drink to obtain a mixture containing 50% pineapple juice?

Let's look at how much pineapple is in it now.
8 times .15= 1.2 quarts
So we take 1.2 from 8 to get 6.8 (non pineapple content)

Now take 6.8-1.2 to get 5.6
So if we add 5.6 pineapple to that 8 quarts let's look at the contents.

Non pineapple= 6.8 quarts
Pineapple= 1.2 + 5.6 = 6.8 quarts
then 6.8 + 6.8 = 13.6 quarts which is a perfect 50% mixture. so your answer is 5.6 quarts.

To solve this problem, we need to understand how much pure pineapple juice is currently in the drink and how much more would need to be added to achieve a 50% pineapple juice mixture.

The given information states that the drink currently contains 15% pineapple juice. To determine how much pineapple juice is in 8 quarts of the drink, we multiply 8 by 0.15:

8 quarts × 0.15 = 1.2 quarts

So, there are currently 1.2 quarts of pure pineapple juice in the 8 quarts of the drink.

Next, we need to calculate the non-pineapple content of the 8 quarts of the drink. We subtract the amount of pineapple juice from the total quantity:

8 quarts - 1.2 quarts = 6.8 quarts

Now, to achieve a 50% pineapple juice mixture, we need to add a certain amount of pure pineapple juice to the existing 8 quarts. Let's call this unknown quantity "X".

Therefore, the non-pineapple content would remain the same at 6.8 quarts, and the total pineapple content would become:

1.2 quarts (current pineapple juice) + X quarts (additional pineapple juice) = 6.8 quarts (non-pineapple content)

Adding the two quantities of pineapple juice together, we get:

1.2 quarts + X quarts = 6.8 quarts

To find the unknown quantity "X", we need to subtract 1.2 quarts from both sides of the equation:

X quarts = 6.8 quarts - 1.2 quarts
X quarts = 5.6 quarts

Therefore, you would need to add 5.6 quarts of pure pineapple juice to the 8 quarts of the drink to obtain a mixture containing 50% pineapple juice.