LSAT-Section-3-Analytical-Reasoning – Section Three : Analytical Reasoning

Reference / correct answer:

From the figure below, it is definite that the person must be C.

General

Let us name the people Abe, Bob, Chad, Dolly, Elisa, Frank, and Gregory as A, B, C, D, E, F, and G, respectively. We can see that there are 3 × 3 = 9 seats, but there are only 7 people. Thus, the only possible way of distributing the 7 people across the 3 rows is that 2 rows would have 2 members each and one row would have 3 members. However, the exact number of people in a particular row is not yet known and further analysis of the statements needs to be done.

1st statement: C and D sit beside each other … (i)

3rd statement: The row in which C and D are sitting, has exactly 2 people sitting in it (since there is no one sitting on the other side of C) … (ii)

2nd statement: Since D sits in the row just behind A's row, the row where D (and C) sits must be either the middle or the last row

5th statement: Since B sits in the last row and the row where C and D sits has only 2 people, C and D must be in the middle row … (iii) Thus, it also follows that A must be in the front row … (iv)

4th statement: We know that neither E nor G sits beside

A. Thus, there are 2 possible scenarios:

If A is in the middle of the front row, none of E or G can sit in the front row; thus, they would sit in the last row … (v) If A is at either end of the front row, only in that scenario can one of E or G also sits in the front row … (vi) Thus, we have:

Also, in the middle row, since C has D on one side and a vacant seat on the other, C must be in the middle position. Thus, we finally have:

This is all that can be deduced from the main stem.

To answer the questions, we need to use the additional information contained in each question.

Reference / correct answer:

It is known that E and G sit in different rows, i.e. the front and back rows (since only C and D sit in the middle row).

We also know from (v) and (vi):

If A is in the middle of the front row, none of E or G can sit in the front row; thus, they would sit in the last row … (v)

If A is at either end of the front row, only in that scenario can one of E or G also sit in the front row … (vi)

Thus, (v) violates the given condition, implying that A sits at either the left or the right end of the front row, allowing one among E and G to sit at the other corner of the front row and the other to sit in the last row. Thus, we have:

Or

Working with the options:

Option [Dolly sits in the middle of the middle row]: From the diagram, D can sit at either the right or the left end of the middle row, and not at the middle of the middle row. – False

Option [Chad and Dolly do not sit immediately beside one another]: From the diagram, D can sit at either the right or the left end of the middle row and C must be in the center. So, C and D must be immediately beside one another. – False

Option [Gregory sits in the middle of the first row]: Since A and G cannot sit together, and A sits at one end of the front row, G cannot take the middle seat of the front row – False

Option [Abe sits in the middle of the front row]: We have already established that A sits at one end of the front row – False

Option [Frank sits in the middle of the front row]: Since in the front row, A is at one end and E/G is at the other end, F can definitely sit in the middle of the front row. –

True

One such possible seating arrangement is shown below:

General

Let us name the people Abe, Bob, Chad, Dolly, Elisa, Frank, and Gregory as A, B, C, D, E, F, and G, respectively. We can see that there are 3 × 3 = 9 seats, but there are only 7 people. Thus, the only possible way of distributing the 7 people across the 3 rows is that 2 rows would have 2 members each and one row would have 3 members. However, the exact number of people in a particular row is not yet known and further analysis of the statements needs to be done.

1st statement: C and D sit beside each other … (i)

3rd statement: The row in which C and D are sitting, has exactly 2 people sitting in it (since there is no one sitting on the other side of C) … (ii)

2nd statement: Since D sits in the row just behind A's row, the row where D (and C) sits must be either the middle or the last row

5th statement: Since B sits in the last row and the row where C and D sits has only 2 people, C and D must be in the middle row … (iii) Thus, it also follows that A must be in the front row … (iv)

4th statement: We know that neither E nor G sits beside

A. Thus, there are 2 possible scenarios:

If A is in the middle of the front row, none of E or G can sit in the front row; thus, they would sit in the last row … (v)

If A is at either end of the front row, only in that scenario can one of E or G also sits in the front row … (vi)

Thus, we have:

Also, in the middle row, since C has D on one side and a vacant seat on the other, C must be in the middle position. Thus, we finally have:

This is all that can be deduced from the main stem.

To answer the questions, we need to use the additional information contained in each question.

Reference / correct answer:

We know that the row in which Frank sits has only 2 persons sitting.

Working with the options:

Option [Frank sits in the last row] If F sits in the last row along with B (who is already sitting in the last row as well), there cannot be anyone else sitting in the last row; since there should be exactly 2 people in that row. Thus, A, G and E must sit in the front row, which is not possible. – False

Option [Frank sits in the front row] If only F sits in the front row along with A, all among B, E and G must be in the last row. Since there is no contradiction for B, E and G

in sitting together, this seating arrangement is correct. – True

Though we have got the correct answer, let us still verify why the remaining choices are incorrect

Option [Bob and Elisa sit beside one another] With B, E and G sitting together, we can have different arrangements in the last row: B-E-G or B-G-E or G-B-E, etc. Thus,

B and E may or may not sit beside one another. Note that this is a 'must be true question,' not a 'may be true' question. – False

Option [Bob and Frank sit beside one another] Since F sits in the front row and B is in the last row, they cannot sit beside one another. – False

Option [Elisa and Gregory sit beside one another] From the same reasoning used for 'option C,' E and G may or may not sit beside one another. So, this option is not necessarily be true. – False

General

Let us name the people Abe, Bob, Chad, Dolly, Elisa, Frank, and Gregory as A, B, C, D, E, F, and G, respectively. We can see that there are 3 × 3 = 9 seats, but there are only 7 people. Thus, the only possible way of distributing the 7 people across the 3 rows is that 2 rows would have 2 members each and one row would have 3 members. However, the exact number of people in a particular row is not yet known and further analysis of the statements needs to be done.

1st statement: C and D sit beside each other … (i)

3rd statement: The row in which C and D are sitting, has exactly 2 people sitting in it (since there is no one sitting on the other side of C) … (ii)

2nd statement: Since D sits in the row just behind A's row, the row where D (and C) sits must be either the middle or the last row

5th statement: Since B sits in the last row and the row where C and D sits has only 2 people, C and D must be in the middle row … (iii) Thus, it also follows that A must be in the front row … (iv)

4th statement: We know that neither E nor G sits beside

A. Thus, there are 2 possible scenarios:

If A is in the middle of the front row, none of E or G can sit in the front row; thus, they would sit in the last row … (v) If A is at either end of the front row, only in that scenario can one of E or G also sits in the front row … (vi) Thus, we have:

Also, in the middle row, since C has D on one side and a vacant seat on the other, C must be in the middle position. Thus, we finally have:

This is all that can be deduced from the main stem.

To answer the questions, we need to use the additional information contained in each question.