A certain hall contains two cuckoo clocks. If the first clock chirps 20 times per hour and the second clock chirps 9 times per hour, and both clocks chirp for the first time at 2:03 pm, at what time will the first clock have chirped three times as many times as the second clock can chirp per hour?  Select the correct option.
A) 2:42 pm  B) 2:50 pm  C) 3:07 pm  D) 3:21 pm  E) 3:30 pm
The question is asking when the first clock will have chirped 27 times (3*9 chirps).   The first clock chirps once every 3 minutes.   If the first chirp is at 2:03, then the 27th chirp is at 81 minutes after 2:00.   The answer is 3:21 pm.
<result>D</result>
A certain hall contains two cuckoo clocks. If the first clock chirps 20 times per hour and the second clock chirps 9 times per hour, and both clocks chirp for the first time at 2:03 pm, at what time will the first clock have chirped three times as many times as the second clock can chirp per hour?