Question 1132015
Total 30 cups
Some at 58%, I'll call this "x"
the rest up to 30 cups are at 37%
You want the final mix to be at 55%
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0.58x + 0.37(30 - x) = 0.55(30)
0.58x + 11.1 - 0.37x = 16.5
0.21x = 5.4
x = 5.4/0.21 Divide to get your answer. Round to the nearest 2 decimals unless you were given other instructions