Answer:
The answer is 7.5 cm.
Explanation:
Since 1 liter = 1,000 cm³, then 9 liters of gasoline = 9,000 cm³.
We know that the base area of the gas tank would be covered by the gasoline, but we have to find the height that would be covered. The base area = length of gas tank × width of gas tank = 40 × 30 = 1,200 cm².
Let x be the height covered so that 1,200x (cm² × cm) = 9,000 cm³ (volume of gasoline in the gas tank)
Therefore, the height that 9 liters of gas will fill in the gas tank = x = 9000 cm³ ÷ 1,200 cm² = 7.5 cm.