Answer:
7.5 liters of a 40% sugat solution
Explanation:
Let
x------> liters of a 40% sugar solution
remember that
40% = 40/100 = 0.40
60% = 60/100 = 0.60
56% = 56/100 = 0.56
we know that the amount of liters of a 40% sugar solution (x) multiplied by 0.40 plus the amount of liters of a 60% sugar solution (30 L) multiplied by 0.60 must be equal to the total amount of liters mixed (x+30) multiplied by 0.56
0.40x + 0.60(30) = 0.56 (x+30)
solve for x
0.40x + 18 = 0.56x +16.8
0.56x - 0.40x = 18 -16.8