00:01
Okay, your pool contains 18 ,000 gallons of water and reduces by half each day.
00:07
How much is left after seven days? okay, let's start answering this question by making a table.
00:31
So i'm going to assume that 18 ,000 gallons, oops, so i've got day and amount in my table.
00:48
I'm going to assume that 18 ,000 gallons is on day 0, because after one day you've leaked half of that amount.
00:59
So how would you figure that out? well, you take 18 ,000 and you would multiply that by one half, and that's how much you'd have.
01:09
You'd have 9 ,000 gallons.
01:11
Makes sense, right? what about day 2? i could take 9 ,000 and multiply by one half, but how about i just take my starting value and multiply it by one half and then multiply it by one half again.
01:28
Two days have passed.
01:29
I'm multiplying it by one half two times.
01:33
So now i'm down to 4 ,500.
01:39
Okay, how about day three? seven isn't that big.
01:43
We could just keep doing it this way, but i'm hoping you'll start to recognize the pattern.
01:49
So on day 3, we could take that original amount.
01:53
On day 4, we got this much, 18 ,000 times 1 half times 1 half on day 2...