Scheduling - Advanced Level: time slots ADVANCED

Exam-focused holistic practice ★ worksheet: 20 advanced-level scheduling questions. Worksheet 23 of 30 targets time slots. Build proficiency in time allocation, day scheduling, timetable puzzles with detailed solutions. Ideal for advanced competitive exam preparation.

📝 Worksheet 23 of 30 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Advanced level

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Worksheet 23 of 30 (76% complete)

Question 1

Five patients need appointments. Their preferences are: - Patient A: Dr. Patel at 10:00 AM - Patient B: Dr. Kumar at 10:00 AM - Patient C: Dr. Patel at 10:30 AM - Patient D: Dr. Shah at 10:00 AM - Patient E: Dr. Patel at 11:00 AM Each doctor can see one patient per 30-minute slot. If all preferences are honored, how many patients need to be rescheduled?
Step-by-step solution:

Conflict Detection Method:
1. Create doctor-time matrix:
Doctor | 10:00 | 10:30 | 11:00 | 11:30
------------|-------|-------|-------|-------
Dr. Patel | A | C | E | ---
Dr. Kumar | B | --- | --- | ---
Dr. Shah | D | --- | --- | ---

2. Check for conflicts:
- Dr. Patel at 10:00: Only Patient A (No conflict)
- Dr. Patel at 10:30: Only Patient C (No conflict)
- Dr. Patel at 11:00: Only Patient E (No conflict)
- Dr. Kumar at 10:00: Only Patient B (No conflict)
- Dr. Shah at 10:00: Only Patient D (No conflict)

3. Verification:
- No doctor has multiple patients in same slot
- All preferences can be honored

Answer: 0 patients need rescheduling

Key Strategy: Map all appointments to a doctor-time grid and identify slots where multiple patients request the same doctor.

Question 2

A football league has 9 teams. Each team plays every other team twice (home and away). What is the minimum number of rounds needed if each round has the maximum possible matches?
Step-by-step solution:

1. Total matches in double round-robin: 9 × (9-1) = 72
2. Maximum matches per round: 4
3. Minimum rounds: 72 ÷ 4 = 9 rounds

Answer: 9 rounds

Question 3

A factory has 4 machines. Each requires 2 day of preventive maintenance every 60 days. If maintenance is staggered, what is the maximum number of machines that can be operational at any time?
Step-by-step solution:

1. Total machines: 4
2. Maintenance duration: 2 day
3. Staggered schedule: Never have all machines down simultaneously
4. Maximum operational: 4 - 1 = 3

Answer: 3 machines

Question 4

A project involves two events, Event A (Meeting) and Event B (Training). The constraints are: - **Event A:** Duration 90 minutes. Must start between 9:00 AM and 11:00 AM. - **Event B:** Duration 60 minutes. Must finish by 3:00 PM. - **Gap:** A minimum of 2 hours is required between the end of Event A and the start of Event B. Assuming all constraints must be met, what is the earliest possible start time for Event B?
Step-by-step solution (Time Arithmetic):

1. Goal: To find the earliest start time for Event B, we must use the earliest possible schedule for Event A.
2. Calculate Earliest Finish Time for Event A:
- Earliest Start for A: 9:00 AM
- Duration of A: 90 minutes (1 hour 30 minutes)
- Earliest Finish for A: 9:00 AM + 1 hour 30 minutes = 10:30 AM.
3. Apply Minimum Gap:
- Earliest Start for B = (Earliest Finish A) + (Minimum Gap)
- Minimum Gap: 2 hours (120 minutes)
- Earliest Start for B: 10:30 AM + 2 hours = 12:30 PM.
4. Check Deadline for Event B:
- If B starts at 12:30 PM, its finish time is 12:30 PM + 60 minutes = 1:30 PM.
- The latest finish time for B is 3:00 PM. Since 1:30 PM is before 3:00 PM, the schedule is valid.
Answer: The earliest possible start time for Event B is 12:30 PM.
Key Strategy: To find the minimum time for the second event, use the minimum time for the first event, plus the mandatory gap.

Question 5

Round Robin scheduling with time quantum = 3: - P1: Burst time 6 - P2: Burst time 7 - P3: Burst time 7 - P4: Burst time 10 What is the average completion time?
Step-by-step solution:

1. Round Robin simulation:
2. Completion times:
- P1: 15
- P2: 25
- P3: 26
- P4: 30

3. Average: 96 ÷ 4 = 24.0

Answer: 24.0

Question 6

A hospital needs to schedule 5 staff for 7 days (Sunday, Monday, Tuesday...). Each day has 3 shifts: Morning, Evening, Night. Undesirable shifts (higher weight = more undesirable): - Weekend Night: weight 3 - Weekend Evening: weight 2 - Any Night: weight 1 After creating a fair schedule, what is the fairness gap (difference between max and min undesirable weights assigned to any staff)?
Step-by-step solution (Fairness Scheduling):

1. Total shifts to assign:
- 7 days × 3 shifts = 21 shifts
2. Shifts per person: 21 ÷ 5 = 4 with 1 extra shifts
3. Undesirable weight distribution:
- Bob: 1 points
- Carol: 3 points
- David: 5 points
- Emma: 3 points
- Frank: 3 points

4. Fairness gap: 5 - 1 = 4

Key Strategy: Fair scheduling aims to minimize the maximum difference in undesirable shift assignments across all staff.

Question 7

Four colleagues need to schedule a meeting. Their available time slots are: - Alex: 9:00 AM, 10:00 AM, 2:00 PM, 3:00 PM - Ben: 10:00 AM, 11:00 AM, 2:00 PM - Cara: 9:00 AM, 11:00 AM, 12:00 PM, 3:00 PM - Diana: 10:00 AM, 12:00 PM, 2:00 PM, 3:00 PM What is the earliest time slot when all four can meet?
Step-by-step solution:

Set Intersection Method:
1. List all availability:
- Alex: {9:00 AM, 10:00 AM, 2:00 PM, 3:00 PM}
- Ben: {10:00 AM, 11:00 AM, 2:00 PM}
- Cara: {9:00 AM, 11:00 AM, 12:00 PM, 3:00 PM}
- Diana: {10:00 AM, 12:00 PM, 2:00 PM, 3:00 PM}

2. Find common slots (intersection):
- Common to all = Alex AND Ben AND Cara AND Diana
- Result: Empty set (No common time)

3. Conclusion: No common time slot available

Key Strategy: Use set intersection to find common availability, then choose the earliest time.

Question 8

A hospital ward has 12 patients. Each nurse can handle at most 3 patients. What is the minimum number of nurses required?
Step-by-step solution:

1. Patients: 12
2. Capacity per nurse: 3
3. Minimum nurses: ⌈12 ÷ 3⌉ = 4

Answer: 4 nurses

Question 9

A passenger travels from Atlanta to Chicago via Miami. The minimum layover at Miami is **90 minutes**. **Flights Atlanta -> Miami:** - F1-1: Dep 9:00 AM, Arr 11:58 AM - F1-2: Dep 12:00 PM, Arr 2:58 PM - F1-3: Dep 3:00 PM, Arr 5:58 PM **Flights Miami -> Chicago:** - F2-1: Dep 12:00 PM, Arr 2:57 PM - F2-2: Dep 2:00 PM, Arr 4:57 PM - F2-3: Dep 4:00 PM, Arr 6:57 PM What is the minimum total elapsed time for the journey from Atlanta to Chicago?
1. Timeline Approach & Constraint Application (Minimum Layover: 90 min):
The fastest total time is found by checking all 9 combinations and ensuring the layover time (F2 Dep Time - F1 Arr Time) is at least the minimum required.

2. Optimal Path Calculation:
The minimum elapsed time of 477 minutes is achieved by combining F1-1 (Arr: 11:58 AM) and F2-2 (Dep: 2:00 PM, Arr: 4:57 PM).
Total Elapsed Time = Final Arrival Time - Initial Departure Time.

3. Final Answer: The minimum elapsed time is 7 hours and 57 minutes.

Question 10

Given these scheduling constraints: - Task D must be before Task A - Task C must be after Task A - Task B must be immediately after Task D Is a valid schedule possible?
Step-by-step solution:

1. Check for cycles: No circular dependencies
2. Check immediate constraints: Can be satisfied
3. Conclusion: Yes, a valid schedule exists

Answer: Yes, a valid schedule exists

Question 11

In a single-elimination knockout tournament with 16 teams, how many total matches are played to determine the champion?
Step-by-step solution:

1. Single elimination principle: Each match eliminates exactly one team
2. Teams to eliminate: 16 - 1 = 15 teams must be eliminated
3. Matches needed: 15 matches

Answer: 15 matches

Question 12

A flow shop has 2 machines (M1 → M2). Jobs and processing times (M1, M2): - Job A: (45, 14) - Job B: (32, 40) - Job C: (20, 21) - Job D: (17, 48) - Job E: (49, 24) Using Johnson's Rule, what is the minimum makespan?
Step-by-step solution (Johnson's Rule):

1. Apply Johnson's Rule:
- If M1 time < M2 time, schedule early
- If M2 time < M1 time, schedule late
2. Optimal sequence: Job E → Job A → Job D → Job C → Job B
3. Calculate makespan: 220

Answer: 220

Question 13

A machine needs to process 4 jobs. Processing times: - Job C: 67 minutes - Job A: 63 minutes - Job B: 80 minutes - Job D: 54 minutes The machine breaks down at 107 minutes and takes 22 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job D → Job A → Job C → Job B
2. Simulate processing with breakdown:
- Job D: 0 → 54
- Job A: Starts at 54, breakdown at 107 (53 min completed), repair 22 min, resume 10 min → completes at 139
- Job C: 139 → 206
- Job B: 206 → 286

3. Total makespan: 286 minutes
4. Delay caused by breakdown: 22 minutes

Answer: 286 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 14

A production line needs to manufacture: - Product A: 1 units (each takes 4 hours) - Product C: 2 units (each takes 3 hours) - Product D: 3 units (each takes 1 hours) Setup time required when switching products: - P->P: 1 hour What is the minimum total time if production starts with Product C?
Step-by-step solution:

Production Sequencing with Setup Times:
1. Calculate total production time (without setup):
- Product A: 1 x 4 = 4 hours
- Product C: 2 x 3 = 6 hours
- Product D: 3 x 1 = 3 hours
- Base production time: 13 hours

2. Minimize setup time by batching:
- Optimal sequence: Product C -> Product C -> Product A -> Product D -> Product D -> Product D
3. Total with setups:
- Product C: 3 hours
- Product C: 3 hours (no setup)
- Setup Product C→Product A: 1 hour + Product A: 4 hours
- Setup Product A→Product D: 1 hour + Product D: 1 hours
- Product D: 1 hours (no setup)
- Product D: 1 hours (no setup)

Total: 15 hours

Key Strategy: Batch identical products together to minimize setup changes.

Question 15

A traveler needs to go from City A to City D. The transport schedule is: - T1: City A to City B, Departs 06:00, Arrives 8:23 AM - T2: City A to City C, Departs 06:30, Arrives 9:28 AM - T3: City B to City D, Departs 15:30, Arrives 6:11 PM - T4: City B to City C, Departs 11:30, Arrives 1:05 PM - T5: City C to City D, Departs 11:30, Arrives 2:29 PM - T6: City C to City B, Departs 14:00, Arrives 4:58 PM - T7: City E to City D, Departs 15:00, Arrives 5:07 PM - T8: City E to City B, Departs 13:00, Arrives 3:01 PM Minimum connection time is 30 minutes. What is the earliest arrival time at City D?
Step-by-step solution:

Network Path Analysis:
1. Identify all possible routes from City A to City D:
- City A→City B -> City B→City D
- City A→City C -> City C→City D
- City A→City B -> City B→City C -> City C→City D

2. Best route found:
- T2: City A to City C (06:30 - 9:28 AM)
- Connection time: 122 minutes
- T5: City C to City D (11:30 - 2:29 PM)

Earliest arrival: 2:29 PM

Key Strategy: Enumerate all possible routes, verify connection times meet minimum requirements.

Question 16

Hospital OR scheduling with 3 operating rooms (8 hours each): - Emergency: 33 min, Priority 1 - Urgent: 84 min, Priority 2 - Elective A: 101 min, Priority 3 - Elective B: 84 min, Priority 3 - Routine: 106 min, Priority 4 Can all surgeries be completed in one day?
Step-by-step solution:

1. Total surgery time: 408 min = 6.8 hours
2. Available OR hours: 3 × 8 = 24 hours
3. Total ≤ Available → Can complete in one day

Answer: All surgeries can be scheduled within one day

Question 17

A machine must process four products (P3, P1, P2, P4) to minimize total time. Processing times: P3: 88, P1: 30, P2: 50, P4: 39 Setup times: | From ↓ / To → | P3 | P1 | P2 | P4 | | P3 | 0 | 10 | 37 | 38 | | P1 | 30 | 0 | 19 | 17 | | P2 | 40 | 26 | 0 | 34 | | P4 | 30 | 22 | 40 | 0 | What sequence minimizes total time?
Optimal sequence examined for all 24 permutations.
Minimum time: 266 minutes. Sequence: P4 - P3 - P1 - P2.
Calculation: P4 → P3 → P1 → P2.
Time: PT(P4) + (ST(P4→P3) + PT(P3)) + ...

Question 18

A clinic operates for 4 hours with 15-minute appointment slots. If 9 patients need appointments, how many can be accommodated?
Step-by-step solution:

1. Total slots available: (4 × 60) ÷ 15 = 16
2. Patients: 9
3. All patients can be scheduled

Answer: All 9 patients can be scheduled

Question 19

A factory has 5 machines. Each requires 2 day of preventive maintenance every 60 days. If maintenance is staggered, what is the maximum number of machines that can be operational at any time?
Step-by-step solution:

1. Total machines: 5
2. Maintenance duration: 2 day
3. Staggered schedule: Never have all machines down simultaneously
4. Maximum operational: 5 - 1 = 4

Answer: 4 machines

Question 20

5 tasks (A, B, C, D, E) are to be completed one after the other. The following conditions must be met: - Task A must be performed immediately after Task C. - Task D must be completed before Task E. - Task B is neither the first nor the last task to be completed. - Task B is performed exactly 1 positions after Task E. Which task is scheduled in the fourth position?
Step-by-step solution (Deductive Logic):

1. Apply Consecutive Constraint: 'A immediately after C' -> (C, A)
2. Apply Before Constraint: 'D before E'
3. Apply Exclusion Constraint: 'B not first or last'
4. Apply Gap Constraints: 'B is 1 after E'

Final Sequence: C → A → D → B → E

Answer: The task in the fourth position is B.

Key Strategy: Use fixed pairs and gap constraints to anchor positions.
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