Barrel water remaining

There are 90 liters of water in the rainwater barrel. Dad drained two-thirds of the barrel. How many liters of water are left in the barrel?

Final Answer:

V =  30 l

Step-by-step explanation:

$$\begin{gathered} V_1=90\text{l} \\ {V}_2=\frac{2}{3}\cdot V_1=\frac{2}{3}\cdot 90=\frac{2\cdot 90}{3}=\frac{180}{3}=60\text{l} \\ V=V_1-V_2=90-60=30\text{l} \end{gathered}$$

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