Psychologists observing a shopping mall parking lot found that, on average, drivers spent 39 seconds leaving a parkin...

Irina on August 29, 2017

Great Video!

This is a great way to explain these games. The only part where I seem to have some trouble is in figuring out, through the longer chain sequences, where to put the letters that have no relationships to each other and what that means.

8 Replies

Mehran on August 31, 2017

Keep practicing! You will get more comfortable with creating the larger chain sequences.

But remember, if you do not know anything about a certain variable, that variable is a random variable.

This effectively means it could go anywhere.

Hope that helps! Please let us know if you have any other questions.

Natalie on June 26, 2018

On question 12, why didn't the instructor try to place O before she came up with the answer? She determined the answer before trying to place O anywhere and I'm confused why she knew she didn't have to do anything with O?

Christopher on June 28, 2018

@Natalie-King, if you can't nail down where exactly J, K, and N go, it's impossible to know exactly where O can be. O's position is entirely dependent on those other relationships, so there's no reason to try to place O, because O can be several different places. Once you determine that J, K, and N can be in a variety of locations, then you can conclude that O is also undetermined and won't count toward the answer you're looking for. Does that make sense?

Justin on October 3, 2018

When organizing the large sequence chain, since we already knew that M would be last, could we have also concluded that N would be next since it was the only variable besides M to have nothing to the right of it?

Mehran on October 16, 2018

@JSheares I am assuming you are referring to the second game in this lesson (soft-drink manufacturer).

If so, that would not be correct because K could also appear sixth.

Does that make sense?

Urbano on December 4 at 03:48AM

I don't understand what question 11 and 12 are asking for on the second game. Please provide explanation.

Jacob on December 5 at 05:07AM

Hi @ulino23

Question 11 has some tricky phrasing. “What is the maximum possible number of the soft drink names any one of which could be among the three most popular?”

What this question is essentially asking is, how many sodas could occupy either slots 1, 2, or 3? And to figure that out, we can ask — which sodas will never occupy any of those slots?

If you follow the video again, you will see that M, K, and O could never been in the three most popular. Every other soda could be in the first three slots, so we know that there are four sodas that can be in the first 3. So B is correct.

Question 12 adds a new rule that P comes before J. And now we are asking, with that additional rule, for which sodas do we know, no matter what, what rank they are in? Because the new rule tells allows us to determine ranks 1, 2, and 7, we can determine three soda slots. And B is correct.

I hope that helps! Let us know if you have further questions.

on June 16 at 01:20AM

I'm not sure what I'm not understanding but I cannot come to the correct answer on the Question 1-5 of February 1992 #6.