A certain clock marks every hour by striking a number of times equal to the hour, and the time required for a stroke is exactly equal to the time interval between strokes. At 6:00 the time lapse between the beginning of the first stroke and the end of the last stroke is 22 seconds. At 12:00, how many seconds elapse between the beginning of the first stroke and the end of the last stroke? A 72, B 50, C 48, D46, E 44

OG 解释中，始终不明白“At 6:00 there are 6 stroke and 5 intervals between strokes. Thus there are 11 equal time intervals in the 22 seconds between the beginning of the first stroke and the end of the last strok." 划线部分。愚啊！让我捶胸顿足！！