00:01
All right, here we're given a couple of supply and demand curves for any market.
00:05
We have a quantity supplied equal to 2p and a quantity demanded equal to 300 minus p.
00:11
We first want to find what this equilibrium is.
00:14
So we know that our equilibrium is going to be the point at which these two points cross.
00:18
And we want to know what our quantity is down here and what our price is at this equilibrium.
00:24
So to do that, we can just set these two curves equal to one another.
00:28
So we can do 2p, set 2p equal to 300 minus p.
00:35
And let's go ahead and solve for p here.
00:38
Adding p to both sides with 3p is equal to 300.
00:41
And dividing both sides by 3 gives us a price, which is equal to 100.
00:46
So there's one piece of our equilibrium.
00:48
Now to find the quantity, we can just plug this back into either our supply or demand curve because we know that that quantity is the same for both.
00:56
So let's plug it into our quantity supplied.
00:58
Which is equal to 2p, so multiplying 2 times 100.
01:03
That gives us a quantity which is equal to 200.
01:06
All right, so these points down here, you can see that we have a quantity of 200 and a price of 100.
01:19
Now let's suppose that the government imposes a price ceiling of $90.
01:24
So that's going to sit somewhere.
01:26
We can see that our equilibrium was 100, so it's now going to sit somewhere beneath that.
01:30
So suppose $90 is right here at a price.
01:35
Price of 90, we want to know whether or not there is a shortage or a surplus that's occurring here or neither if that's the case.
01:43
What we can see here is that our new quantity supplied sits here and our new quantity demanded is going to sit over here.
01:52
That's at that price.
01:54
So it seems pretty obvious right here that when our supply and our quantity demanded over here that we have some gap that exists.
02:04
So that's going to be the shortage that we're running into.
02:07
But let's determine how much that shortage actually is.
02:11
So all we need to do is plug our price of 90 into our quantity demanded and our quantity supplied functions.
02:19
So doing that, we have our quantity supplied with the price of 90 is 2 times 90.
02:26
It tells us that our quantity supplied is 180.
02:30
To the same for our quantity demanded, which is 300 minus 90.
02:38
That gives us a quantity demanded, which is equal to 210.
02:42
210, sorry, if i can do basic math.
02:45
So what we can see here now is that there's a $30 unit difference here...