This problem involves arranging seven boxes (A, B, C, D, E, F, G) in a vertical stack based on several conditions. We need to determine the final arrangement to find out how many boxes are placed below box A.
Let's break down the given conditions and apply them step-by-step to figure out the stack arrangement:
We can represent the stack with 7 positions, numbered 1 (bottom) to 7 (top).
Using Condition 1, E is at position 3. Using Condition 2, D is at position 6.
Current Stack:
| 7: | Empty |
| 6: | D |
| 5: | Empty |
| 4: | Empty |
| 3: | E |
| 2: | Empty |
| 1: | Empty |
Using Condition 3, there's one box between D (position 6) and B. This means B must be at position 4.
Current Stack:
| 7: | Empty |
| 6: | D |
| 5: | Empty |
| 4: | B |
| 3: | E |
| 2: | Empty |
| 1: | Empty |
Using Condition 4, G is immediately above C. The only remaining adjacent empty slots are positions 1 and 2. Therefore, C is at position 1 and G is at position 2.
Current Stack:
| 7: | Empty |
| D | |
| Empty | |
| B | |
| E | |
| G | |
| C |
The remaining boxes are A and F. The remaining positions are 5 and 7.
Using Condition 5, F must be below A. So, A must be placed at the higher available position (7) and F at the lower available position (5).
Final Stack Arrangement:
| 7: | A |
| 6: | D |
| 5: | F |
| 4: | B |
| 3: | E |
| 2: | G |
| 1: | C |
From the final arrangement, we can see that box A is at the topmost position (position 7).
The boxes positioned below A are D, F, B, E, G, and C.
Counting these boxes, we find there are 6 boxes below A.
Each of P, Q, R, S, T, U and V has an exam on a different day of a week, starting from Monday and ending on Sunday of the same week. U has an exam on Friday. Only 2 people have exams between U and R. V has an exam immediately before Q and T has an exam immediately after S. Only 2 people have exams between P and Q. Who has an exam on Sunday?