A square field ABCD of side 90 m is so located that its diagonal AC is from north to south and the B is to the west of D. Rohan and Rahul start walking along the sides from B and C respectively in the clockwise and anticlockwise directions with speeds of 8 km/hr and 10 km/hr. Where shall they cross each other the second time ?

Options

A. On AD at a distance of 30 m from A
B. On BC at a distance of 10 m from B
C. O n AD at a distance of 30 m from D
D. On BC at a distance of 10 m from C

Answer

D

Explanation

The arrangement is as shown in the Fig.

Rohan takes the route BADCB at 8 km/ hr
`=20/9` m/sec
Rahul takes the route CDABC at 10 km/hr
`=25/9m`/sec
`because` AB = BC = CD = DA = 90 m
First time they meet when Rohan travels 120 m and Rahul travels 150 m. For the second time, Rohan is 10 m towards B from C or Rahul is 80 m towards C from B.
Therefore, on BC at a distance of 10 m from C they cross each other the second time.