Question 1
Five boxes P, Q, R, S, and T of different sizes are stacked vertically (positions 1 to 5 from bottom to top).
The stacking rule is: larger boxes must be placed below smaller boxes.
Size relationships:
- Box P is larger than box Q but smaller than box R
- Box S is the smallest
- Box T is larger than box R
- Box Q is larger than box S
If box S is removed from the stack, which box will be at position 4 (counting from the bottom)?
Step-by-step Solution:
1. Establish size relationships:
- P > Q and R > P → So R > P > Q
- S is smallest → S is less than all others
- T > R
- Q > S
2. Combine all inequalities:
- From T > R and R > P > Q, we get: T > R > P > Q
- From Q > S, we get: T > R > P > Q > S
3. Complete size order (largest to smallest):
T > R > P > Q > S
4. Apply stacking rule (larger below smaller):
- Position 1 (bottom): T (largest)
- Position 2: R
- Position 3: P
- Position 4: Q
- Position 5 (top): S (smallest)
5. Remove box S from position 5:
6. Remaining stack (4 boxes):
- Position 1: T
- Position 2: R
- Position 3: P
- Position 4: Q
7. Answer: Box Q is at position 4
Verification:
- T > R ✓ (pos1 vs pos2)
- R > P ✓ (pos2 vs pos3)
- P > Q ✓ (pos3 vs pos4)
- Q > S ✓ (pos4 vs pos5 before removal)
1. Establish size relationships:
- P > Q and R > P → So R > P > Q
- S is smallest → S is less than all others
- T > R
- Q > S
2. Combine all inequalities:
- From T > R and R > P > Q, we get: T > R > P > Q
- From Q > S, we get: T > R > P > Q > S
3. Complete size order (largest to smallest):
T > R > P > Q > S
4. Apply stacking rule (larger below smaller):
- Position 1 (bottom): T (largest)
- Position 2: R
- Position 3: P
- Position 4: Q
- Position 5 (top): S (smallest)
5. Remove box S from position 5:
6. Remaining stack (4 boxes):
- Position 1: T
- Position 2: R
- Position 3: P
- Position 4: Q
7. Answer: Box Q is at position 4
Verification:
- T > R ✓ (pos1 vs pos2)
- R > P ✓ (pos2 vs pos3)
- P > Q ✓ (pos3 vs pos4)
- Q > S ✓ (pos4 vs pos5 before removal)