Solve this problem by doing dimensional analysis.
Start with your given (the number you are given):
21 hours
Next, obtain some conversion ratios/factors. There are 60 minutes in 1 hour. There also 60 seconds in 1 minute.
21 hours x 60 minutes/1 hour x 60 seconds/1 minute
Multiply and divide it out to get 75600 seconds.
5 years 21 days 4 hours 32 minutes and 17 seconds = 159,615,367.00146776438 seconds.
34281 seconds = 9 hours 31 minutes and 21 seconds.
1505 seconds is 25 minutes and 5 seconds Add 25 minutes to 751 giving 776 minutes. This is 12 hours and 31 minutes Add 12 hours to 21 hours. This is 33 hours, that is 1 day and 9 hours. So we have 1day 09hours 00minutes 00seconds + 0day 12hours 31minutes 00seconds + 0day 00hours 05minutes 05seconds _____________________________ 1day 21hours 36minutes 05seconds _____________________________
122400 seconds
72000 seconds
21 hours has 75,600 seconds.
21 hours is equal to 75,600 seconds.
5 years 21 days 4 hours 32 minutes and 17 seconds = 159,615,367.00146776438 seconds.
34281 seconds = 9 hours 31 minutes and 21 seconds.
9 hours 21 minutes 09 seconds - 3 hours 46 minutes 54 seconds =5 hours 34 minutes 15 seconds
6 hours equals 360 minutes so multiply that by 6 for each minute and you get 21,000 then 21 times 60 and you get 1,260 so ad them together and you get 22,260 seconds!
7 days, 21 hours, 8 minutes, 30 seconds 7.88 days
21 days = 1814400 seconds
1505 seconds is 25 minutes and 5 seconds Add 25 minutes to 751 giving 776 minutes. This is 12 hours and 31 minutes Add 12 hours to 21 hours. This is 33 hours, that is 1 day and 9 hours. So we have 1day 09hours 00minutes 00seconds + 0day 12hours 31minutes 00seconds + 0day 00hours 05minutes 05seconds _____________________________ 1day 21hours 36minutes 05seconds _____________________________
122400 seconds
72000 seconds
1209600 seconds