A bell rings every 18 minutes. A second bell rings every 24 minutes. A third bell rings every 32 minutes. Ifall the three bells ring at the same time at 8 o'clock in the morning, at what other time will they all ring together?
(a) 12 : 40 hrs (b) 12 : 48 hrs (c) 12 : 56 hrs (d) 13 : 04 hrs