00:01
If we have a half life of three hours, the way that we write that using an exponent would be one half, and then up here in the exponent will be t over three.
00:10
So we have 500 milligrams, and so our equation would be the amount that we have is 500 times one half and then t over three.
00:20
So to answer the first question of how much we're going to have of 24 hours, it would be the amount is 500 times one half and then the t over 3.
00:30
Would be 24 over 3.
00:33
Or in other words, we're going to do 500 and then one half to the eighth power because 24 divided by 3 is 8.
00:41
So then our next step here is just to evaluate that to be 500 times 0 .5 to the eighth power.
00:46
And what i get is 1 .953.
00:52
And it doesn't specify the rounding.
00:55
So i'm going to go ahead and just leave it like that.
00:56
So we have a 1 .953 milligrams.
00:59
So that would be the first answer here for the 24 hours.
01:03
All right.
01:03
So the second one wants to know, when is it going to be less than one milligram? so i'm going to find out when is it equal to one milligram...