LSAT Logic Games : Determining sequence in linear games

Study concepts, example questions & explanations for LSAT Logic Games

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Example Questions

Example Question #251 : Sequencing

Future Tech Industries employs exactly two scientists: P and Q. The company also employs exactly three engineers: R, S, and T. On a workday all five employees must use the company lab exactly once, according to the following conditions:

Only one employee uses the lab at a time.

Each employee focuses their research on either energy or health, but not both.

Employee P focuses on health.

Employees Q and R focus on energy.

All health focused employees use the lab before any energy focused employees.

Any energy focused engineer uses the lab before any energy focused scientist.

The employee that uses the lab second could be any one of exactly how many employees?

Possible Answers:

Two

Four

Three

One

Five

Correct answer:

Four

Explanation:

Because P focuses on health it must come before Q and R. And because Q is both energy focused and scientist there are no employees allowed to use the lab after Q. The game can thus be written three ways:

P __ __ __ Q

__ P __ __ Q

__ __ P R Q 

In the first way, R, S, T are interchangeable and can all be placed second. The second way shows P can go second. Thus, the only employee to not be able to go second is Q.

Example Question #252 : Sequencing

Future Tech Industries employs exactly two scientists: P and Q. The company also employs exactly three engineers: R, S, and T. On a workday all five employees must use the company lab exactly once, according to the following conditions:

Only one employee uses the lab at a time.

Each employee focuses their research on either energy or health, but not both.

Employee P focuses on health.

Employees Q and R focus on energy.

All health focused employees use the lab before any energy focused employees.

Any energy focused engineer uses the lab before any energy focused scientist.

Which one of the following could be the order, from first to last, in which the five employees use the lab?

Possible Answers:

T, S, R, P, Q

P, Q, T, S, R

   P, S, T, Q, R

P, Q, R, S, T

P, S, T, R, Q

Correct answer:

P, S, T, R, Q

Explanation:

All the incorrect answers are wrong for the following reasons:

P, Q, R, S, T (Since Q and R are both energy focused, and Q is a scientist and R is a engineer R must use the lab before Q)

P, Q, T, S, R (Since Q and R are both energy focused, and Q is a scientist and R is a engineer R must use the lab before Q)

P, S, T, Q, R (Since Q and R are both energy focused, and Q is a scientist and R is a engineer R must use the lab before Q)

T, S, R, P, Q (P is health focused, whereas R is energy focused, thus P must use the lab before R)

Example Question #252 : Sequencing

A talent show has seven teams of performers, each named after a color of the rainbow: Red, Orange, Yellow, Green, Blue, Indigo, and Violet. Four teams perform in Act I and three teams perform in Act II. They apply the following rules to determine the lineup of the talent show:

  • Violet must be in Act I.
  • Green either performs first or last.
  • Exactly one team performs between Yellow and Blue.
  • Violet performs some time after Blue.

All of the following could be true except:

Possible Answers:

Green performs last.

Yellow performs second.

Red performs fifth.

Yellow performs fourth.

Blue performs first.

Correct answer:

Yellow performs second.

Explanation:

If Violet performs after Blue, but Violet must be in Act I, then Blue must also be in Act I. That means that Blue can go first, second, or third in the lineup.

  • If Blue goes first, Yellow must go third because there is exactly one act between them.
  • If Blue goes second, Yellow must go fourth for the same reason.
  • If Blue goes third, Yellow must go first for the same reason.

There is no possible case, then, in which Yellow goes second.

Example Question #253 : Sequencing

A talent show has seven teams of performers, each named after a color of the rainbow: Red, Orange, Yellow, Green, Blue, Indigo, and Violet. Four teams perform in Act I and three teams perform in Act II. They apply the following rules to determine the lineup of the talent show:

  • Violet must be in Act I.
  • Green either performs first or last.
  • Exactly one team performs between Yellow and Blue.
  • Violet performs some time after Blue.

If Blue performs second, which of the following must be true?

Possible Answers:

Yellow performs fifth.

Violet performs third.

Red performs last.

Orange performs first.

Indigo performs sixth.

Correct answer:

Violet performs third.

Explanation:

If Blue performs second, and there is exactly one act between Blue and Yellow, then Yellow must perform fourth. Since Violet performs after Blue but still performs in Act I, yet there are only four acts in Act I, Violet must perform third.

Example Question #251 : Sequencing

A college is having an event for alumni who graduated in the years 2005-2010, inclusive. Six friends-- Harry, Inez, Jack, Katie, Lou, and Maria-- attend the event.
  • Katie graduated in 2006.
  • Harry and Maria graduated the same year.
  • Nobody graduated in 2007.
  • Katie graduated before Jack, but after Lou.

Which of the following could not be true?

Possible Answers:

Harry graduated in 2006.

Maria graduated in 2005.

Jack graduated in 2009.

Inez graduated in 2010.

Lou graduated in 2008.

Correct answer:

Lou graduated in 2008.

Explanation:

Since Katie graduated after Lou, and Katie graduated in 2006, Lou must have graduated in 2005. Therefore, Lou did not graduate in 2008.

Example Question #255 : Sequencing

A talent show has seven teams of performers, each named after a color of the rainbow: Red, Orange, Yellow, Green, Blue, Indigo, and Violet. Four teams perform in Act I and three teams perform in Act II. They apply the following rules to determine the lineup of the talent show:

  • Violet must be in Act I.
  • Green either performs first or last.
  • Exactly one team performs between Yellow and Blue.
  • Violet performs some time after Blue.

 

If Red performs last, which of the following must be true?

 

Possible Answers:

Orange performs in Act II.

Yellow performs in Act I.

Indigo performs in Act II.

Green performs in Act I.

Yellow performs in Act II.

Correct answer:

Green performs in Act I.

Explanation:

Since Red performs last, and Green can only perform first or last in the lineup, Green must go first. Therefore, Green performs in Act I.

Example Question #252 : Sequencing

A restaurant manager is scheduling interviews for an Executive Chef at her new business. Interviews for six applicants--Chet, Sylvia, Dennis, Beulah, Henrietta, and Lester--will be scheduled, one interview per day for the next six days. The schedule for the interviews is subject to the following conditions:

Lester must be scheduled to interview earlier than Sylvia.

Dennis must be scheduled to interview earlier than both Chet and Beulah.

The interviews scheduled for the second and third days cannot be for either Chet, Beulah, or Henrietta.

Henrietta's interview cannot be scheduled for the sixth day.

Which one of the following is an acceptable schedule of interviews, listed in order from earliest to latest?

Possible Answers:

Lester, Henrietta, Dennis, Chet, Beulah, Sylvia

Henrietta, Lester, Dennis, Sylvia, Chet, Beulah

Henrietta, Dennis, Sylvia, Chet, Lester, Beulah

Chet, Lester, Dennis, Henrietta, Sylvia, Beulah

Dennis, Lester, Sylvia, Chet, Beulah, Henrietta

Correct answer:

Henrietta, Lester, Dennis, Sylvia, Chet, Beulah

Explanation:

In order to solve this problem, simply go through each answer and apply each individual condition from the pre-question text. If the answer violates any of the conditions, then you can eliminate it. If the answer does not violate any conditions, then you know it is correct. A question like this will typically be the first in its set, and is an opportunity to solidify your knowledge of the conditions governing the game. 

For this problem, the correct order is: Henrietta, Lester, Dennis, Sylvia, Chet, Beulah

Let's go through the list of conditions to see why:

"Lester must be scheduled to interview earlier than Sylvia." TRUE

"Dennis must be scheduled to interview earlier than both Chet and Beulah." TRUE

"The interviews scheduled for the second and third day cannot be for either Chet, Beulah, or Henrietta.TRUE

"Henrietta's interview cannot be scheduled for the sixth day.TRUE

This is the only provided sequence that satisfies every condition of the game, and is therefore the correct answer. 

Example Question #256 : Sequencing

A restaurant manager is scheduling interviews for an Executive Chef at her new business. Interviews for six applicants--Chet, Sylvia, Dennis, Beulah, Henrietta, and Lester--will be scheduled, one interview per day for the next six days. The schedule for the interviews is subject to the following conditions:

Lester must be scheduled to interview earlier than Sylvia.

Dennis must be scheduled to interview earlier than both Chet and Beulah.

The interviews scheduled for the second and third days cannot be for either Chet, Beulah, or Henrietta.

Henrietta's interview cannot be scheduled for the sixth day.

If neither Chet nor Beulah nor Henrietta is scheduled to interview on the fourth day, which one of the following must be true?

Possible Answers:

Lester is scheduled to interview on the second day.

Beulah is scheduled to interview on the sixth day. 

Henrietta is scheduled to interview on the first day.

Dennis is scheduled to interview on the third day.

Chet is scheduled to interview on the fifth day. 

Correct answer:

Henrietta is scheduled to interview on the first day.

Explanation:

The key to finding the correct solution to this problem is drawing additional deductions from the question text. In addition to the conditions given to us in the pre-question text, we know that in the sequence we are solving for, neither Chet nor Beulah nor Henrietta can occupy the fourth position. This will allow us to make secondary deductions about their relative positions in the sequence by combining this information with the previous conditions. Let's start by looking at the third condition from the pre-question text:

"The interviews scheduled for the second and third day cannot be for either Chet, Beulah, or Henrietta."

When we combine this condition with the new information in the question, we see that neither Chet nor Beulah nor Henrietta can occupy the second, third, or fourth positions in our sequence. This leaves only the first, fifth, and sixth positions to place these three entities. Next, let's look at the second condition.

"Dennis must be scheduled to interview earlier than both Chet and Beulah."

We now know that Chet, Beulah, and Henrietta must occupy the first, fifth, and sixth positions in the sequence. However, when we apply the second condition of the pre-question text, we see that neither Chet nor Beulah may occupy the first position, as this would make it impossible for the second condition to be true. This leaves only Henrietta to fill the first position in the sequence, meaning that it must be true that Henrietta is interviewed on the first day. Therefore, this is the answer we are looking for.

Now, questions like this can get confusing because of their phrasing. After all, through our own deductions we have established that Chet could be interviewed on the fifth day, and that Beulah could interview on the sixth day. However, for the answer to this question to be considered correct, it is not sufficient that an answer could be true. Rather, the answer must be true in every possible iteration of the sequence. Chet and Beulah are interchangeable in the fifth and sixth positions, and therefore do not meet the criteria for a correct answer.

Example Question #254 : Sequencing

A restaurant manager is scheduling interviews for an Executive Chef at her new business. Interviews for six applicants--Chet, Sylvia, Dennis, Beulah, Henrietta, and Lester--will be scheduled, one interview per day for the next six days. The schedule for the interviews is subject to the following conditions:

Lester must be scheduled to interview earlier than Sylvia.

Dennis must be scheduled to interview earlier than both Chet and Beulah.

The interviews scheduled for the second and third days cannot be for either Chet, Beulah, or Henrietta.

Henrietta's interview cannot be scheduled for the sixth day.

Which one of the following must be true?

Possible Answers:

Lester is scheduled to interview earlier than Chet.

Henrietta is scheduled to interview earlier than Lester.

Henrietta is scheduled to interview earlier than Chet.

Dennis is scheduled to interview earlier than Sylvia.

Sylvia is scheduled to interview earlier than Henrietta. 

Correct answer:

Lester is scheduled to interview earlier than Chet.

Explanation:

The answer to this problem will be a condition that must be true. Therefore, this condition will always be true, in any viable iteration of the sequence of interviews. Any answer that does not meet this criteria can be automatically eliminated. 

The correct answer from the options provided is: Lester is scheduled to interview earlier than Chet.

We need to look at the conditions from the pre-question text to determine why this is correct. Let's start with the second condition:

"Dennis must be scheduled to interview earlier than both Chet and Beulah."

Because we know that at least one entity (Dennis) must precede Chet in the sequence, we know with certainty that he cannot occupy the first position. Now let's combine this information with the third condition:

"The interviews scheduled for the second and third days cannot be for either Chet, Beulah, or Henrietta."

When we add this information from the third condition into the mix, we see that Chet cannot occupy either the first, second, or third positions in the sequence. Conversely, this means that Chet can only occupy the fourth, fifth, or sixth positions. Now that we've established Chet's potential positions in the sequence, let's look at the first condition, which concerns Lester.

"Lester must be scheduled to interview earlier than Sylvia."

Because we know that Lester must precede at least one entity (Sylvia) in the sequence, we can deduce that he cannot occupy the sixth position in the sequence. Since we also already know that Chet can only occupy the fourth, fifth, or sixth position in the sequence, we can further deduce that the only conceivable way for Chet to precede Lester in the sequence would be for Chet to occupy the fourth position and Lester to occupy the fifth. If this sequence violates any of the other conditions, then we will know that we've found the correct answer. Let's test it out. 

_ _ _ C L _

Since the first condition tells us that Lester must precede Sylvia, we know that Sylvia must occupy the sixth position in the sequence.

_ _ _ C L S

Furthermore, we know from the third condition that the only remaining position for Henrietta to occupy is the first. She must occupy this position.

H _ _ C L S

This is where the sequence breaks down. According to the third condition, neither Chet nor Beulah nor Henrietta can occupy the second or third positions of the sequence. However, with Beulah as one of our remaining entities, our only remaining positions in the sequence are the second and third. Since we have determined through our deductions that this is the only conceivable way for Chet to precede Lester in the sequence, it is impossible for Chet to come before Lester. Therefore, it must be true that Lester is scheduled to interview earlier than Chet.

Example Question #255 : Sequencing

A restaurant manager is scheduling interviews for an Executive Chef at her new business. Interviews for six applicants--Chet, Sylvia, Dennis, Beulah, Henrietta, and Lester--will be scheduled, one interview per day for the next six days. The schedule for the interviews is subject to the following conditions:

Lester must be scheduled to interview earlier than Sylvia.

Dennis must be scheduled to interview earlier than both Chet and Beulah.

The interviews scheduled for the second and third days cannot be for either Chet, Beulah, or Henrietta.

Henrietta's interview cannot be scheduled for the sixth day.

Which of the following CANNOT be the interviews scheduled for the fourth, fifth, and sixth days, listed in that order?

Possible Answers:

Sylvia, Beulah, Chet

Henrietta, Beulah, Chet

Dennis, Beulah, Chet

Chet, Beulah, Sylvia

Lester, Chet, Sylvia

Correct answer:

Lester, Chet, Sylvia

Explanation:

The phrasing of the question text is intended to make this question more difficult. Before looking at the answer choices, we should take a second to parse what the question is really asking, and what will determine a correct answer. Because the question is asking us for an order that CANNOT work within the conditions of the game, the correct answer will contain an error. Apply each condition to each potential answer. The first time you encounter an error, you will know you have found your correct answer. 

The correct choice for this question is: Lester, Chet, Sylvia.

Let's apply the conditions from the pre-question text to this response to see why it is the right choice.

"Lester must be scheduled to interview earlier than Sylvia."

No error so far. In this sequence, Lester is scheduled to interview earlier than Sylvia. Let's go on to the second condition.

"Dennis must be scheduled to interview earlier than both Chet and Beulah."

This is where we encounter a problem. Because Lester, Chet, and Sylvia occupy the fourth, fifth, and sixth positions (respectively), we know that the only remaining positions to fill are the first, second, and third. No matter which remaining position Dennis occupies, he will always precede Chet, so that's not the problem. The problem is that Dennis must also precede Beulah, meaning that Beulah must occupy either the second or third position. However, as we know from the third condition:

"The interviews scheduled for the second and third days cannot be for either Chet, Beulah, or Henrietta."

Therefore, it is impossible for Beulah to occupy either of the remaining positions, and this response CANNOT be true

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