plz hurry.......

In case we need to find out when exactly will hey meet again we can calculate their actual speeds as, 2 kmph,2.5 kmph,3 kmph.

Relative gain of second cyclist over first one is 0.5 km/h and that of fastest one is 1 km/h. Clearly 2nd will catch first in 360/0.5 h=720 h and 3rd will catch first in 360/1 h= 360 h. SImilarly, third will catch 2nd in 720 h.

Hence all of them will be simultanously at same point next after 720 h or 30 days.