# Economists Do It With Models

## Videos: Introducing Econ 101 Practice Problems…

#### September 23rd, 2011 · 3 CommentsEcon 101 · Videos

One of the surprising things about my video project is that I get a fair number of messages from viewers asking me about particular questions that they encountered in their courses. I can tell that some viewers just want me to do their homework for them, but others have genuine issues that they are confused about that likely apply to a whole bunch of students. Therefore, I decided to start responding to this latter group via video, and I’ve put the first two here for your viewing pleasure:

Elasticity Practice Problem 1:

I’ve been given the equation for the quantity demanded and the quantity supplied. The simplified versions look like this:
Qd = 400 – 4p
Qs = -200 + 6p
The Equilibrium Price is 60 and the Quantity demanded is 160. In order to get the PED, should I replace the “p” in the equation for the quantity demanded for a random number, lets say, 50, and see how much the QD changes?

Comparative Statics Practice Problem 1:

What will happen to the equilibrium price and equilibrium quantity of notebook computers if the number of colleges that require their students to buy a notebook computer increases at the same time as the number of firms producing notebook computers decreases?

You can see the complete playlist here, and you can see the overall EDIWM YouTube channel here. You can also see more info about the videos via the Econ 101 Videos link above. If you are a student, and especially if you are an instructor, I encourage you to submit questions that you think would be helpful for a general audience to see.

Tags: Econ 101 · Videos

### 3 responses so far ↓

• 1 Ron Cronovich // Sep 23, 2011 at 5:23 pm

If students are required to buy computers, wouldn’t that make the D curve steeper?

Instead of thinking of the policy as altering buyer’s tastes, could we think of it as causing an increase in the number of buyers?

Thank you!

• […] this latter group via video, and I’ve put the first two here for your viewing pleasure:..”Show original Share this:TwitterFacebookLike this:LikeBe the first to like this […]

• 3 http://www.vinfriends.com/BradleyFuller/info/ // Jun 26, 2014 at 10:51 pm

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