Answer: 20 quarts of peanut oil worth 19 cents a quart must be mixed.
Explanation:
Let x represent the number of quarts of peanut oil worth 19 cents a quart that would be in the mixture.
The total number of quarts in the mixture would be x + 100
The cost of the x quarts would be x × 19 = 19x cents
The cost of 100 quarts of the other peanut oil would be 25 × 100 = 2500 cents
The cost of the mixture would be
24(x + 100) = 24x + 2400
Therefore, the equation would be
19x + 2500 = 24x + 2400
24x - 19x = 2500 - 2400
5x = 100
x = 100/5
x = 20