Question

4 weeks 3 days 13 hours 21 minutes
- 2 weeks 6 days 19 hours 31 minutes
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This is a subtraction

Answer 1

change 1 week in the 4 weeks to 7 days

3weeks 10 days 13 hrs 21 min
then change one day to 24 hrs
3 weeks 9 days 37 hrs 21 min
then change one hour to 60 min
3 weeks 9 days 36 hrs 81 min
now subtract .

Answer 2

first "borrow" a week
3 weeks, 10 days, 13 hours, 21 minutes
now borrow a day
3 weeks, 9 days, 37 hours, 21 minutes
now borrow 1 hour
3 weeks, 9days, 36 hours, 81 minutes
now we can subtract ...
2weeks, 6days,19 hours, 31 minutes

= 1 week, 3 days, 17 hours, 50 minutes

Answer 3

This is a very good question!