How many gallons of cream which is 10% butterfat must be added to 15 gallons of cream which is 20% butterfat to obtain cream which is 16% butterfat?

Oh, the delightful world of dairy math! Let me calculate that for you, but first, let's have a moment of silence for all the lactose intolerant souls out there.

To obtain a cream mixture that is 16% butterfat, we need to determine how much 10% butterfat cream to add to 15 gallons of 20% butterfat cream.

So let's get down to business. We'll use "x" to represent the gallons of cream to be added.

The amount of butterfat in the 10% cream can be calculated as 0.10x, and the amount in the 20% cream can be calculated as 0.20(15).

Now, when we mix these together, the total butterfat in the mixture will be 0.10x + 0.20(15). And this mixture should equal 16% of the total volume, which is 15 + x gallons.

Putting it all together:

0.10x + 0.20(15) = 0.16(15 + x)

Now we just need to solve the equation and find the value of "x."

0.10x + 3 = 2.4 + 0.16x

Rearranging a bit:

0.10x - 0.16x = 2.4 - 3

-0.06x = -0.6

Dividing both sides by -0.06:

x = 10

Hurray! The solution is in! You need to add 10 gallons of 10% butterfat cream to 15 gallons of 20% butterfat cream to obtain 16% butterfat cream... and keep in mind, folks, no dairy-themed clown acts were harmed in the making of this solution!

To find out how many gallons of cream with 10% butterfat need to be added to 15 gallons of cream with 20% butterfat to obtain cream with 16% butterfat, we can use a weighted average formula.

Let's assume x gallons of cream with 10% butterfat are needed.

The amount of butterfat in 15 gallons of cream with 20% butterfat is 15 * 20% = 3.

The amount of butterfat in x gallons of cream with 10% butterfat is x * 10% = 0.1x.

The amount of butterfat in the final mixture (15 + x gallons) with 16% butterfat is (15 + x) * 16% = 0.16(15 + x).

According to the weighted average formula, the sum of the butterfat in the initial mixtures is equal to the butterfat in the final mixture:

3 + 0.1x = 0.16(15 + x).

Now, let's solve this equation to find x:

3 + 0.1x = 2.4 + 0.16x.

Subtracting 0.1x from both sides, we get:

3 = 2.4 + 0.06x.

Subtracting 2.4 from both sides, we get:

0.6 = 0.06x.

Dividing both sides by 0.06, we get:

x = 0.6 / 0.06 = 10.

Therefore, 10 gallons of cream with 10% butterfat must be added to 15 gallons of cream with 20% butterfat to obtain cream with 16% butterfat.

To find out how many gallons of cream with 10% butterfat need to be added to 15 gallons of cream with 20% butterfat to obtain cream with 16% butterfat, you can use the method of solving mixtures.

Let's assume x gallons of cream with 10% butterfat are added to the existing 15 gallons of cream with 20% butterfat.

The total volume of the mixture will be given by:

15 + x

The percentage of butterfat in the mixture will be given by:

(15 * 20 + x * 10) / (15 + x) = 16

Now, we can solve this equation to find the value of x.

15 * 20 + 10x = 16 * (15 + x)

300 + 10x = 240 + 16x

6x = 60

x = 10

Therefore, 10 gallons of cream with 10% butterfat should be added to 15 gallons of cream with 20% butterfat to obtain cream with 16% butterfat.

(15 * .20) + (x * .10) = (15 + x) * .16