At exactly what time past 8:00 will the minute and hour hands of an accurate working clock be precisely perpendicular to each other for the first time?	Pick.
A) 20 13/21 minutes past 8:00 B) 20 13/17 minutes past 7:00 C) 21 3/23 minutes past 7:00 D) 21 9/11 minutes past 7:00 E) 22 4/9 minutes past 7:00
20 13/21 minutes past 8:001 = hour angle   20 13/21 minutes past 8:002 = minute angle   20 13/21 minutes past 8:001-20 13/21 minutes past 8:002 = 90   20 13/21 minutes past 8:00ssume the minutes = M   20 13/21 minutes past 8:001 = (8*60+M)/12*60 )*360   20 13/21 minutes past 8:002 = M*360/60   Solving all three equation , results in the answer 20 13/21 minutes past 8:00
<result>A</result>
At exactly what time past 8:00 will the minute and hour hands of an accurate working clock be precisely perpendicular to each other for the first time?