Six friends A, B, C, D, E and F are sitting in two lines, facing the north. Three persons are sitting in each line. F is sitting in the middle. C is just behind B. D is to the immediate right of E. B is to the immediate left of F. Which three persons are sitting in the same line?
C, D and E
This question is a classic seating arrangement puzzle where we need to figure out the positions of six friends based on the given clues. There are six friends: A, B, C, D, E, and F. They are sitting in two lines, with three persons in each line, all facing north. Since they are facing north, the line behind the first line is towards the south from the perspective of someone facing north.
Analyzing the Seating Arrangement Clues
Let's break down the information given:
- Six friends: A, B, C, D, E, F.
- Two lines, three persons per line.
- Everyone is facing north. This means one line is in front of the other. Let's call the front line Line 1 and the back line Line 2. Line 2 is behind Line 1.
Now, let's look at the specific clues about their positions:
- Clue 1: F is sitting in the middle. (This means F is in the middle seat of either Line 1 or Line 2).
- Clue 2: C is just behind B. (This tells us B and C are in different lines, with C in the line behind B).
- Clue 3: D is to the immediate right of E. (D and E are in the same line, next to each other).
- Clue 4: B is to the immediate left of F. (B and F are in the same line).
Deducing the Seating Positions
Let's use the clues to figure out where everyone is sitting:
- From Clue 4 (B is to the immediate left of F) and Clue 1 (F is in the middle), we know B and F are in the same line. Since F is in the middle, the arrangement in that line starts with B F. Let's represent the line positions as Left, Middle, Right. So, this line looks like: B F _
- Now consider Clue 2 (C is just behind B). Since B is in the arrangement B F _, B is likely in the front line (Line 1). If B were in the back line (Line 2), C being behind B wouldn't make sense for people facing north; C would be in front. So, B is in Line 1, and C is in Line 2.
- If B is in Line 1 and is to the immediate left of F (who is in the middle), Line 1 must be: B F _. The third person in Line 1 sits to the immediate right of F.
- Now we know C is in Line 2. C is just behind B. B is in the leftmost position of Line 1 (relative to the middle). So, C must be in the corresponding leftmost position of Line 2 (relative to the middle of Line 2).
- Consider Clue 3 (D is to the immediate right of E). D and E must be in the same line. Since Line 1 already has B and F (and one other spot), D and E must be in Line 2.
- Line 2 needs to accommodate C, E, and D. C is in the leftmost position. D is immediately to the right of E. The only way to arrange C, E, and D in three seats with C leftmost and D immediately right of E is: C E D.
- So, Line 2 is C E D (Left, Middle, Right).
- Line 1 is B F _. We have accounted for B, C, D, E, and F. The only remaining person is A.
- A must occupy the remaining spot in Line 1, which is to the immediate right of F.
- Therefore, the final arrangement is:
| Left Position | Middle Position | Right Position | |
|---|---|---|---|
| Line 1 (Front) | B | F | A |
| Line 2 (Back) | C | E | D |
This arrangement fits all the clues:
- F is in the middle (of Line 1).
- C is just behind B (B is leftmost in Line 1, C is leftmost in Line 2).
- D is to the immediate right of E (in Line 2).
- B is to the immediate left of F (in Line 1).
Identifying Persons in the Same Line
The question asks which three persons are sitting in the same line. Based on our deduced arrangement:
- Line 1 contains: A, B, F.
- Line 2 contains: C, D, E.
Now let's check the given options to find the group of three who are in the same line:
- C, D and E: These three are all in Line 2.
- B, C and D: B is in Line 1, C and D are in Line 2. Not in the same line.
- A, F and C: A and F are in Line 1, C is in Line 2. Not in the same line.
- A, B and D: A and B are in Line 1, D is in Line 2. Not in the same line.
The only option where all three persons are in the same line is C, D and E, who are all in Line 2.
Revision Table: Seating Arrangement Clues
| Clue | Interpretation | Deduction |
|---|---|---|
| Six friends, two lines of three, facing north | Total 6 people, 2 rows of 3 seats. One line is behind the other. | Setup: Line 1 (Front) _, _, _; Line 2 (Back) _, _, _. |
| F is sitting in the middle | F is in the middle seat of either line. | F is either Line 1, Middle or Line 2, Middle. |
| B is to the immediate left of F | B and F are in the same line, next to each other. | The line contains B F _. |
| C is just behind B | B and C are in different lines; C is in the line behind B. | If B is in Line 1, C is in Line 2. If B is in Line 2, C is in Line 1. B must be in Line 1 for C to be behind (facing North). |
| Putting B, F, C together | B is in Line 1 (Left/Middle based on F), F is in Line 1 (Middle). C is in Line 2, in the position behind B. | Line 1: B F _. Line 2: C in position behind B. |
| D is to the immediate right of E | D and E are together in the same line. | D and E must be in Line 2 (as Line 1 has B, F, A). Arrangement E D in Line 2. |
| Arranging C, E, D in Line 2 | C is in the position behind B (Left). E and D are together (E D). | Line 2 must be C E D (Left, Middle, Right). |
| Remaining person and spot | A is left. Spot next to F in Line 1 is left. | Line 1 is B F A. |
Additional Information on Seating Arrangement Puzzles
Seating arrangement questions are common in logical reasoning sections of various exams. They test your ability to follow clues and deduce positions based on spatial relationships. Key aspects to remember include:
- Direction: Pay close attention to which direction people are facing (North, South, East, West, or towards/away from the center). This determines their left and right sides.
- Relative Positions: Words like "immediate left/right", "to the left/right", "behind", "in front of", "opposite" are crucial. "Immediate" means next to, with no one in between.
- Line vs. Circle: Puzzles can involve linear arrangements (like in lines or rows) or circular arrangements. The approach differs slightly.
- Visualization: Drawing the arrangement (lines, circles, seats) as you deduce positions is often very helpful to avoid errors.
- Elimination: As you place people, you eliminate possibilities for their positions and the positions of others.
- Multiple Possibilities: Sometimes, a clue might lead to two possible arrangements. You need to carry both possibilities forward until a subsequent clue eliminates one. In this puzzle, the clue "C is just behind B" along with "facing North" helped eliminate B being in the back row immediately.
Practice with different types of seating arrangements helps improve speed and accuracy in solving these logic puzzles.
Important Questions from Number Arrangement
In the series 5442673314884743581, the number of 4s that are completely divisible by the number on their right but not divisible by the number on their left is:
Refer to the following series and answer the question (all numbers are single digit numbers only).
(Left) 1 2 6 5 6 8 1 5 8 6 9 8 3 3 5 8 9 4 7 8 (Right)
How many such even digits are there, each of which is immediately preceded by an odd digit and also immediately followed by an odd digit?
Each of the digits in the number 9362145 is arranged in ascending order from left to right. What will be the sum of the digits which are second from the left and third from the right in the number thus formed?
If 1 is added to each odd digit and 2 is subtracted from each even digit in the number 3842675, how many digits will appear more than once in the new number thus formed?
Refer to the following number and symbol series and answer the question that follows. Counting to be done from left to right only.
(Left) @ * $ 3 8 9 % + 7 > 6 # < % % ? 6 2 $ / 6 (Right)
How many such numbers are there, each of which is immediately preceded by a symbol and also immediately followed by a symbol?
