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 intrval betwween 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 last stroke?
(A)72
(B)50
(C)48
(D)46
(E)44
Ans:D
題目有點看不太懂的說
