00:01
So for part a, we have to find n when r is 0 .9.
00:05
So we can just, that's pretty, just read and do.
00:09
So that's an n equals negative 7600, log, and then r is 0 .9.
00:22
So it's 0 .9.
00:25
All right, we can just plug that into a calculator, and we'll get an is approximately 6 .0, log 0 .9.
00:41
347 .76.
00:43
And our units are years.
00:53
Years.
00:53
The answer here, our units are years.
00:56
That's a seven.
00:58
All right, for part b, same thing.
01:01
Except r is now 0 .3.
01:04
So n is equal to negative 7600, log 0 .3, equals equals so n is approximately 3973 .888 years and then last but not least we'll do part c again i don't have to erase everything because the questions are somewhat similar so we'll just do this and then we don't know okay so this question might be a little bit more challenging because it's using words instead of just telling you what are equals but it says now, how many, find how many years have elapsed? so we know n is year...