Question

Shawn's clock is 4 minutes slower in an hour. He sets it to be the correct time at 8:00pm, and he sets the alarm to be 5:55am tomorrow morning. What time will the alarm go off tomorrow? Round your answer to the nearest minute.

Answer 1

Alarm will go off at actual time of approximately 6:40 am

Explanation:

If the clock is 4 minutes slower, it means that if an actual time passes by 1 hour and 4 minutes, the clock will show 1 hours.

We can use this relation to get define actual time and clock on time.

If we want to see how much the clock is late per minute, we can find that by:

4/40 = 0.067mins late per 1 minute

As clock is corrected at 8:00 pm. Caculate time on clock with respect to actual times.

Actual time: 9:04 pm , Time on clock = 9:00pm

Actual time: 10:08 pm , Time on clock = 10:00pm

Actual time: 11:12 pm , Time on clock = 11:00pm

Actual time: 12:16 am , Time on clock = 12:00am

Actual time: 1:20 am , Time on clock = 1:00am

Actual time: 2:24 am , Time on clock = 2:00am

Actual time: 3:28 am , Time on clock = 3:00am

Actual time: 4:32 am , Time on clock = 4:00am

Actual time: 5:36 am , Time on clock = 5:00am

Actual time: 6:40 am , Time on clock = 6:00am

For 6:00 am on the clock , actual time is 6:40 am

To calculate for 5:55 am, find how much late the clock be for 5 mins

(0.067)(5) = 0.335 min

Substract with from actual time 6:40 , and round off to nearest minute, we'll get the same answer

So alarm will go off at actual time of approximately 6:40 am