0.4 liters of grade A wine, 0.3 liters of grade B wine and 0.8 liters of grade C were mixed to form grade X wine. The cost of grades A, B and C were $17.20, $22.60 and $14.80 per liter respectively. What was the cost of 8 liters of grade X wine?

$ . 00

The cost of (0.4 + 0.3 + 0.8 = 1.5) liters of grade X wine: 0.4 × 17.20 + 0.3 × 22.60 + 0.8 × 14.80 = 25.50

Then, the cost of each liter of grade X wine: 25.50 ÷ 1.5 = 17

Thus, the cost of 8 liters of grade X wine: 17 × 8 = 136