You need to prepare 120 g of a 7% cream using a 21% stock cream and a 2% cream base.
Let x = grams 2%
and 120-x = grams 21%
---------------
2x + (120-x)*21 = 120*7
Solve for x and 120-x
thank you
To prepare 120 g of a 7% cream, we can use a weighted average formula based on the percentages of the stock cream and the cream base. Here's how to calculate it:
1. Let's assume x grams of the 21% stock cream will be used.
2. Since the total desired weight is 120 g, the remaining weight will be (120 - x) grams of the 2% cream base.
To find the amount of the stock cream needed, we can set up the equation:
(Percentage of stock cream * Weight of stock cream) + (Percentage of cream base * Weight of cream base) = (Percentage of desired cream * Total weight of cream)
Using the given values:
(0.21 * x) + (0.02 * (120 - x)) = 0.07 * 120
Simplifying the equation:
0.21x + 2.4 - 0.02x = 8.4
Combine like terms:
0.19x + 2.4 = 8.4
Subtract 2.4 from both sides:
0.19x = 6
Divide by 0.19:
x = 31.6
Therefore, you would need 31.6 grams of the 21% stock cream and (120 - 31.6) = 88.4 grams of the 2% cream base to prepare 120 g of a 7% cream.