00:01
So here we have a story about elasticity.
00:02
Let's remember what elasticity is.
00:04
The elasticity of demand is the percent change in quantity demanded over the percent change in the price of the good.
00:10
That is the definition of price elasticity of demand.
00:13
We're told that this is two, right? and then we are told that there's a 0 .1 percent increase in the price of the good.
00:22
We're told that the percent increase in the price of the good is equal to 0 .1 percent.
00:28
What does that tell us, right? this tells us, well, that the percent change in quantity demanded is equal to two times the percent change in the price, which is equal to two times 0 .1 percent, which is equal to 0 .2 percent.
00:44
In particular, this should also be a negative, right? that's what we call the law of demand.
00:51
As the price goes up, the quantity goes down.
00:54
Unfortunately, economists and question writers are very lazy and leave off the negative side...