1. An airplane consumes $140 \mathrm{~L}$ of fuel flying $680 \mathrm{~km}$. Under similar conditions, how far can it fly on 240 L? (3 marks)

Step 1 ：Let's find the fuel consumption rate per kilometer: \(\frac{140 \mathrm{~L}}{680 \mathrm{~km}} = 0.20588235294117646 \mathrm{~L/km}\)

Step 2 ：Now, let's find the distance the airplane can fly on 240 L of fuel: \(0.20588235294117646 \mathrm{~L/km} \times 240 \mathrm{~L} = 1165.7142857142858 \mathrm{~km}\)

Step 3 ：\(\boxed{1165.71 \mathrm{~km}}\)