00:01
So we have a manufacturer that sells 7 ,000 units per year.
00:08
And this is an electronics company, units a year.
00:13
And it believes that each year, 2 % of the units that have been sold will become inoperative.
00:19
So 2 % inoperative, which means only 98 % of what was sold in previous year will be operative.
00:34
And so what we want to do is figure out how.
00:40
Many units will be in use after in years.
00:47
So let's kind of play around with this.
00:48
So we have the first year selling, we'll get 7 ,000.
00:53
And then the next year, so 7 ,000, it'll be 7 ,000.
01:00
And then it's going to be selling another 7 ,000 plus we have 98 % of that previous year.
01:08
7 ,000.
01:11
And then the next year will be another 7 ,000.
01:15
And then we're going to add to that another 98 % of this, whatever this amount is.
01:24
And then we're going to do a 7 ,000 plus 0 .98 times whatever this is.
01:33
So this is the algorithm.
01:35
And so we're doing the same thing over and over and over and over again.
01:38
So if we think about this as a series, we're essentially taking, if we kind of factor out the 700, 7 ,000 from each of these, so we get, so 7 ,000 times one, you get 7 ,000 times 1 plus 0 .98 to the first, and then we take another 7 ,000 out, hang out, i forget the amount here, times some amount out, then we factor a 7 ,000...