The pilot

The pilot is on a mission with 160 liters of fuel. The distance between the main base and the operation area is 2 hours. The distance between the main base and backup base is 1 hour.
Assume:
- Aircraft fuel consumption is 10 lt/h.
- Minimum fuel after landing should be not less than 43 lt.
- Climb fuel is 10 lt.
- Landing fuel is 2 lt.
For how long time can you continue on that mission?

Correct answer:

t =  7.5 h

Step-by-step explanation:

$$\begin{gathered} V_0=160-43-10-2=105\text{l} \\ {t}_0=\frac{V_0}{10}=\frac{105}{10}=\frac{21}{2}=10.5\text{h} \\ {t}_1=2\text{h} \\ {t}_2=1\text{h} \\ t=t_0-t_1-t_2=\frac{21}{2}-2-1=\frac{15}{2}\text{h}=7.5\text{h} \end{gathered}$$

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