Grades 11-12 Video Solutions 2012-2012_11-12

Video Transcription

A clock has three hands of different length, for hours, for minutes, and for seconds. We do not know which hand is which, but we do know that the clock runs correctly.  At 12.55 and 30 seconds, the hands were in the positions shown to the right. Which of the pictures shows this clock at 8.10?  So let's take a look at what these hands are supposed to be. So this is supposed to be 12.55 and 30 seconds. So the hand between the 12 and 1 has to be the hour hand.  The one pointing to the 6 has got to be the 30 seconds that it's showing. And so then this one has to be the minute hand, which is pointing to the 11, which is 55 minutes, for sure.  Okay, so we have hours, minutes, seconds. Now we just have to line them up on one of these clocks. So it's 8.10, so we know that the middle hand has to be pointing to the 8.  So it's like this one, this one, yeah, those are the only two. And we know that the second hand has to be pointing to 0. So this is the short hand, which is pointing to 0 up here.  And that narrows it down entirely. It's this one.

Video Summary

The transcript describes a problem-solving exercise to identify the configuration of a clock's hour, minute, and second hands at 8:10, starting from a known configuration at 12:55 and 30 seconds. At 12:55, the hour hand was between 12 and 1, the second hand on the 6, and the minute hand on the 11. To determine the correct clock for 8:10, they identified that the hour hand should point to 8, the minute hand to 2, and the second hand to 12. Out of the given options, only one clock matched this description.

Keywords

clock configuration

problem-solving exercise

hour minute second hands

time identification

correct clock