Multiple choice

Sarah and Ryan, have identical digital watches. Sarah's watch always keeps perfect time, while Ryan's watch runs slightly slow. On March 1st, Ryan sets his watch to the correct time at 9:00 AM but after 5 days it shows 5:00 AM instead of showing 9:00 AM. What time will Ryan's watch display on 1st March at 9:00 PM?

  1. 8:36 PM

  2. 8:42 PM

  3. 8:46 PM

  4. 8:48 PM

  5. 8:58 PM
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A Correct answer
Explanation

Ryan's watch loses 4 hours in 5 days (120 hours). Loss rate = 4/120 = 1/30 hours per hour. From 9:00 AM to 9:00 PM is 12 hours. The watch loses 12 * (1/30) = 0.4 hours = 24 minutes. 9:00 PM - 24 minutes = 8:36 PM.

AI explanation

Ryan's watch loses 4 hours over 5 days (120 hours), meaning it runs at a rate of 116 hours for every 120 true hours (29 hours for every 30 hours). To find what his watch displays at 9:00 PM (12 true hours after 9:00 AM), we multiply 12 true hours by the ratio 29 / 30, yielding 11.6 hours. This means the watch shows 11 hours and 36 minutes after 9:00 AM, making the displayed time 8:36 PM.

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