the green watch runs 1 minute fast each hour. the yellow watch runs 2 minutes slow each hour. on wednesday morning the green watch shows 7:20am, while the yellow watch shows 6:20am. at what correct time on tuesday were the watches last set together?
11 AM Tuesday
To solve this problem, we need to find out the time difference between the green and yellow watches. Since the green watch runs 1 minute fast each hour and the yellow watch runs 2 minutes slow each hour, the time difference between them is 3 minutes per hour (1 minute fast + 2 minutes slow).
On Wednesday morning, the green watch shows 7:20 am while the yellow watch shows 6:20 am. The time difference between them is 1 hour (7:20 am - 6:20 am). Since the time difference between the watches is 3 minutes per hour, we can calculate the number of hours it took for the watches to have a 1-hour time difference.
1 hour / 3 minutes = 20 hours
This means that it took 20 hours for the green watch to run 1 hour ahead of the yellow watch. So, the last time the watches were set together would be 20 hours before Wednesday morning, which would be Tuesday morning.
To find the correct time on Tuesday when the watches were last set together, subtracting 20 hours from 6:20 am would give us the answer.
6:20 am - 20 hours = 10:20 am
Therefore, the correct time on Tuesday when the watches were last set together was 10:20 am.