There are 60 hours in 2 and 1/2 days
48
7 and one half hours = 15 half hours. There are 24 hours in a day, so there are 48 half hours in a day. Therefore the answer is 15/48, which can then be reduced to 5/16.
1/2It is 12/24 which can be simplified to 1/2 a day
.25 mg
0.25 mg
Half of an hour = 1/2 hour...(1) Hours in a day = 24 hours and 1 hour = 1/24 day...(2) From the above two results, we get Half of an hour = (1/2)/24 day = 1/48 day
48
7 and one half hours = 15 half hours. There are 24 hours in a day, so there are 48 half hours in a day. Therefore the answer is 15/48, which can then be reduced to 5/16.
12 hours = 1/2 day
If you take one day equal to 24 hours, then 1 day constitutes 2 Half lives. Mass of isotope left after 12 hours=10/2=5g Mass of isotope left after 2 half lives or 1 day=5/2=2.5g.
2.5/24 = 5/48
2 to 3 hours a day
There are 24 hours in a day and night.24 x 2.5 = 60 hours
Roughly 2 hours or on a good day an hour and a half.
24 is divisible by 2, 3, 4, 6, 8 and 12 so that it is easy to define half a day, a sixth of a day etc. 13 is a prime so even half a day would require working out half an hour.
2 hours if you want
2 half hours would be 1 hour