Rita travelled 1200 km by air, which formed $\frac{2}{5}$ th of her journey. One-third of the whole journey she travelled by car and the remaining journey by train. Find the distance travelled by the train.
(a)480 km
(b)800 km
(c)1600 km
(d)1800 km
Answer
Answer (as printed): B
Explanation
Let the total length of the journey be $x$ km. Then, $\frac{2}{5} x=1200 \Leftrightarrow x=\frac{1200 \times 5}{2}=3000$. Distance travelled by car $=\left(\frac{1}{3} \times 3000\right) \mathrm{km}=1000 \mathrm{km}$. ∴ Distance travelled by train $=[3000-(1200+1000)]$ $\mathrm{km}=800 \mathrm{km}$.