Let the length of mini-van be ‘N’ m and the speed of the van be ‘A’ km/h A mini-van crosses people walking at the speed of 4.8 km/h in the same direction as that in which the mini-van is heading in 4.5, ⇒ N/(A - 4.8) = 1/800 ⇒ 800N = A - 4.8 ----1 A mini-van crosses two people walking at the speed of 6 km/h in the same direction as that in which the mini-van is heading in 9 s, ⇒ N/(A - 6) = 1/400 ⇒ 400N = A - 6 ----2 Solving equation 1 and 2, ⇒ 400N = 1.2 km ⇒ N = 3 m ∴ The length of the mini-van is 3 m.