Answer:
2.5 ML
Explanation:
1. Convert gallons to litres
There are 3.785 L in 1 US gal.
[tex]\text{No. of litres} = \text{660 000 gal} \times \dfrac{\text{3.785 L}}{\text{1 gal}} = \text{2 500 000 L}[/tex]
2. Convert litres to megalitres
[tex]\text{No. of megalitres} = \text{2 500 000 L} \times \dfrac{\text{1 ML}}{\text{1 000 000 L}} = \textbf{2.5 ML}[/tex]