Question

The owner of a health food store combined cranberry juice that cost $7.79 per quart with apple juice that cost $7.19 per quart. how many quarts of each were used to make 10 quarts of cranberry juice mixture costing $7.61 per quart

Answer 1

7.79x + 7.19(10-x) = 7.61(10)
x = 7

so,
7 quarts at 7.79
3 quarts at 7.19

makes sense, since 7.61 is near to 7.79