SOLUTION: I have two watches with a 12 hour cycle. one gains a minute each day and the other looses one and a half minutes per day. if i set them both on the correct time, how long will it t

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: I have two watches with a 12 hour cycle. one gains a minute each day and the other looses one and a half minutes per day. if i set them both on the correct time, how long will it t      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1117746: I have two watches with a 12 hour cycle. one gains a minute each day and the other looses one and a half minutes per day. if i set them both on the correct time, how long will it take before next together tell the correct time? (3 marks)
Answer by ikleyn(52903) About Me  (Show Source):
You can put this solution on YOUR website!
.
1.  12 hours = 12 * 60 minutes = 720 minutes.

    Therefore, watch A, set once on the correct time, will displays the correct time exactly after every 720 days.



2.  Also,  12 hours = 720 minutes = 12 * 1.5 minutes *40 = 480 * 1.5 minutes.

    Therefore, watch B, set once on the correct time, will displays the correct time exactly after every 480 days.



3.  Hence, the two watches A and B, set once on the correct time simultaneously, will display (will read) the correct time 

    simultaneously every  LCM(480,720) days = 1440 days.


    LCM = Least Common Multiple.