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3 short tasks about the clock, which is in a hurry and late
3 short tasks about the clock, which is in a hurry and late
Anonim

Calculate what time the arrows will show in a day, try to set the alarm precisely and not miss an important call.

3 short tasks about the clock, which is in a hurry and late
3 short tasks about the clock, which is in a hurry and late

Problem 1

Sergei bought a watch with hands in the store, and at home noticed that they were 20 seconds behind an hour. By nature, Sergei is an experimenter, so he took and set the hour and minute hands to exactly 12. What time will the clock show in a day?

1. For 1 hour, the clock lags behind by 20 seconds, for 3 hours - by 1 minute.

2. There are 24 hours in a day. This means that for 1 day the clock will lag behind by 24 ÷ 3 = 8 minutes.

3. If the clock did not lag behind, in a day the hands would converge again at around 12. But the clock is lagging behind and will show the following time: 12 hours - 8 minutes = 11 hours 52 minutes.

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Problem 2

Sergei's clock began to lag behind by 5 minutes per hour. It is now 6 in the morning, and exactly at noon he has an important work phone call. For how long does Sergey need to set the hands of the clock so that at 12 noon they show the correct numbers?

There are 6 hours left before the call. For 1 hour the clock is 5 minutes behind, for 6 hours it will be 30 minutes behind. This means that the hands need to be moved forward half an hour, that is, at 6:30.

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Problem 3

Sergei discovered that his watch has an alarm clock. Going to bed, he set the exact time on the clock - 22:00. How long does it take to set the alarm so that it rings at exactly 6 in the morning, if the clock is now in a hurry by 9 minutes a day?

Sergey will sleep for 8 hours, from 22:00 to 6:00. For a day, the hours go ahead by 9 minutes, and for 8 hours the difference will be 24 ÷ 8 = 3 minutes. This means that at 6:00, when Sergei needs to wake up, the clock will show 6:03. At this time, you need to start the alarm.

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