Answer:
45 litres
Step-by-step explanation:
Let the whole tank contains x litres of water.
Therefore,
[tex] \frac{2}{3} x = 80 \\ \\ x = 80 \times \frac{3}{2} \\ \\ x = 40 \times 3 \\ \\ x = 120 \\ \\ \frac{3}{8} x = \frac{3}{8} \times 120 \\ \\ = 3 \times 15 \\ \\ = 45 \: liters[/tex]
