Shivani started her homework assignment at a particular time between 3 and 4’O clock. When she completed her assignment between 5 and 6’O clock, she found the hour and minute hand positions to be the same as those of the minute and hour hands respectively when she started her assignment. How long did she spend on the assignment? (Clock)

• shivani started between 3 and 4 so the hour hand is between 3 and 4 .
  and said that she finished between 5 and 6 . so the hour hand gets complete revolution of 360 degree for 1 times and another rotation of 360-x degree. if the angle between hour hand and minute when she started is x degree.
  so total revolution of 720-x degree.
  in 1 hour minute hand moves 6 degree/min and hour hand .5degree/min.
  therefore according to the problem,
  (720-x)/6=x/.5
  or,x=720/13 degree
  
  then the time she spend = x/.5=1440/13=110 10/13.
• 9 years agoHelpfull: Yes(0) No(0)
• for this kind of problems generalized equation to find the angle is (360 * time difference)/13.
  then put the value of x in the equation x/.5 to get the total time .
  for example in this problem time difference is either (5-3) or (6-4) which is equal to 2 ...
• 9 years agoHelpfull: Yes(0) No(3)
• Lets say she started at 3.25.
  so as per the condition, she must have completed at 5.15 because the condition is given that hour and the minute hand will interchange when she completes the homework.
  so total time taken is 1hour and 50 minute
• 7 years agoHelpfull: Yes(0) No(0)