Correct Answer: 384 km.
Explanation:
Let the length of total journey be y km.From question ( y/2 x 1/40 ) + ( y/2 x 1/60) = 8 ⇒ y/80 + y/120 = 8 ⇒ 3y + 2y = 1920 ∴ y = 384 km.