00:01
So let's see what we know here, right? at the beginning, we know that the price was equal to 89.
00:06
We know that the quantity was equal to 40.
00:10
And then now we see that the new, there's a sale of 30%.
00:15
So the new price is equal to 89 times 0 .7, right? it is 30 % less.
00:24
And so if i plug that into a calculator, i get the new price being 62 .3.
00:34
Right.
00:35
And the sale now was quantity equals to 100.
00:41
So let's think about the two things, right? we need elasticity.
00:45
Elasticity is the percentage change in quantity over the percentage change in price.
00:50
Right? that's just the definition how much quantity reacts to changes in price.
00:55
We can get the percentage change in quantity very easily, right? it's 100 minus 40 over 40, which is equal to 150%, right? that was straightforward, nice round numbers.
01:08
But the change in price is a little bit messier, right? the new price is 62 .3.
01:13
The old price was 89.
01:14
We set that relative to the old price of 89...