SOLUTION: My mom’s clock is running fast one second per minute and my dad’s clock is running slow one second per minute. When I left, their clocks were the same and I returned when their c

Algebra ->  Average -> SOLUTION: My mom’s clock is running fast one second per minute and my dad’s clock is running slow one second per minute. When I left, their clocks were the same and I returned when their c      Log On


   



Question 1129654: My mom’s clock is running fast one second per minute and my dad’s clock is running
slow one second per minute. When I left, their clocks were the same and I returned
when their clocks were a minute apart. How long was I away?

Found 2 solutions by ankor@dixie-net.com, josmiceli:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
My mom’s clock is running fast one second per minute and my dad’s clock is running slow one second per minute.
When I left, their clocks were the same and I returned when their clocks were a minute apart.
How long was I away?
:
30 min, the two clocks were 2 sec per min apart

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
1 sec / min = 5 sec / 5 min
--------------------------
I will compare each clock with a 3rd clock
which is running on time. Then I will see
when the 2 original clocks are 1 min apart
I will start when all 3 clocks are at 12:00
--------------------------
(1) = on time clock
(2) = 1 sec/min slow clock
(3) = 1 sec/min fast clock
------------------------------
(1) - - - - - (2) - - - - - (3) - - - - - - - - - difference
12:00 - - 12:00:00 - - - 12:00:00 - - - - - 0 sec
12:05 - - 12:04:55 - - - 12:05:05 - - - - - 10 sec
12:10 - - 12:09:50 - - - 12:10:10 - - - - - - 20 sec
12:15 - - 12:14:45 - - - 12:15:15 - - - - - - 30 sec
12:20 - - 12:19:40 - - - 12:20:20 - - - - - - 40 sec
12:25 - - 12:24:35 - - - 12:25:25 - - - - - - 50 sec
12:30 - - 12:29:30 - - - 12:30:30 - - - - - - 60 sec ( 1 min )
--------------------------------------------------------------------
In a half-hour ( 12:30 ), the 2 clocks show 1 min difference
Another way to look at it is that the difference between them
1 sec / min + 1 sec/min = 2 sec/min
and
2 sec/min = 60 sec / 30 min