Let's define,
X := Total minutes it takes to fill the plane (with fuel)
Then,
[tex]X\cdot0.20=12.40[/tex]Solving it for X, we get
[tex]X=\frac{12.40}{0.20}=62\text{ min}[/tex]This means that the vehicle takes 1 h 2 min to fill the plane. If the fuelling finished at 10:35, it began at
[tex]10-1\colon35-2=9\colon33[/tex]9:33.