5. For an old clock, the minute hand and the hour hand overlap every 66 minutes of standard time. Therefore, in 24 hours of this old clock, compared to 24 hours of standard time, it ( ).
(A) is 12 minutes fast
(B) is 6 minutes fast
(C) is 6 minutes slow
(D) is 12 minutes slow
【Answer】D
【Question Type】Clock Problem
【Analysis】The hour hand moves at a speed of 0.5 degrees per minute, and the minute hand moves at a speed of 6 degrees per minute. Every time the minute hand completes an extra full circle (360 degrees) compared to the hour hand, the two hands overlap once. This happens every $\frac{360}{6-0.5}=\frac{720}{11}$ minutes, which corresponds to 66 minutes in standard time; thus, in 24 hours of the old clock, it is equivalent to $\frac{(24 \times 60)}{\frac{720}{11}} \times 66=1452$ minutes in standard time, which is 12 minutes more than the 1440 minutes (24 hours) in standard time, meaning it is 12 minutes slow.