Alok, Binny and Chintu start to walk together from the same place round a circular path of length 15 km. Alok walks at the rate of 5 km/hr, Binny at the rate of 3 km/hr and Chintu, at the rate of 15/2 km/hr. They will meet at the starting place at the end of –
1
20 hrs
2
25 hrs
3
30 hrs
4
35 hrs