4. (15 points) A tanker is being filled with oil at a rate of 2 barrels per half minute. Given that 1 barrel equals 159 liters, determine the filling rate of the tanker in m ${ }^{3} /$ hour.
Answer: $38.16 \frac{M^{3}}{\psi}$

Solution. $\quad 2 \frac{\text { barrels }}{\frac{1}{2} \text { min }}=2 \frac{159 \text { liters }}{\frac{1}{120} \psi}=2 \cdot 159 \cdot 10^{-3} \cdot 120 \frac{\mathcal{M}^{3}}{\psi}=38.16 \frac{\mathcal{M}^{3}}{\psi}$.