Tillo L asked:
Grandma’s watch gains 30 minutes every hour, while Grandpa’s watch loses 30 minutes every hour. If at midnight both set their watches to the correct time, what time will it be when the watches next agree?
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Grandma’s watch gains 30 minutes every hour, while Grandpa’s watch loses 30 minutes every hour. If at midnight both set their watches to the correct time, what time will it be when the watches next agree?
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Kansieo.com
7:30
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12 hours later Granny’s watch will read 6pm, and Gramp’s will read 6am. But 24 hours later they’ll both read 12 o’clock, but Granny’s will already be one day ahead!
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Hmm…
at 8 am, both grandma and grandpa’s watches will read 4 o’clock.
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12 pm. Grandma’s watch will say 6 pm, Grandpa’s watch will say 6 am.
I’m sure there’s a better/faster way of solving this algebraically, but I wrote out what each watch will say every hour. M is for GrandMa, P is for GrandPa.
12 am=
M- 12 am
P- 12 am
1 am=
m- 1:30 am
p- 12:30 am
2 am=
m- 3 am
p- 1 am
3 am-
m- 4:30 am
p- 1:30 am
4 am-
m- 6 am
p- 2 am
5 am-
m- 7:30 am
p- 2:30 am
6 am-
m- 9 am
p- 3 am
7 am-
m- 10:30 am
p- 3:30 am
8 am-
m- 12 pm
p- 4:00 am
9 am-
m- 1:30 pm
p- 4:30 am
10 am-
m- 3 pm
p- 5:00 am
11 am-
m- 4:30 pm
p- 5:30 am
12 pm-
m- 6 pm
p- 6 am
Kansieo.com
The rule is easy to remember Spring Forward and Fall Back. So in the fall (now) we turn our clocks back an hour. and in the spring we move it forward.
Good Luck!