Who among the students created an incorrect schedule for preparation?

To determine who created the incorrect schedule, we need to analyze the teacher's recommendations and compare them with each student's schedule. Teacher's recommendations: - 60 minutes for daily problem-solving. - 30 minutes for watching video lessons. - 30 minutes for memorizing definitions. - 30 minutes for reading a math theory book. Total recommended study time per day = 60 + 30 + 30 + 30 = 150 minutes (2.5 hours). Let's analyze each student's schedule: Vladislav's Schedule:

• Reading math theory book: 15:00 - 15:30 (30 minutes) - Matches recommendation
• Watching video lessons: 16:00 - 16:30 (30 minutes) - Matches recommendation
• Problem-solving: 18:00 - 18:30 (30 minutes) and 21:00 - 21:30 (30 minutes) = 60 minutes total - Matches recommendation
• Memorizing definitions: 20:00 - 20:30 (30 minutes) - Matches recommendation

Vladislav's schedule includes all recommended activities with the correct durations. Ivan's Schedule:

• Reading math theory book: 18:00 - 18:30 (30 minutes) - Matches recommendation
• Watching video lessons: 16:00 - 16:30 (30 minutes) - Matches recommendation
• Problem-solving: 20:00 - 20:30 (30 minutes) - Does NOT match recommendation (only 30 mins instead of 60 mins)
• Memorizing definitions: 21:00 - 21:30 (30 minutes) - Matches recommendation

Ivan's schedule only allocates 30 minutes for problem-solving, which is half of the recommended 60 minutes. Anna's Schedule:

• Reading math theory book: 7:30 - 8:00 (30 minutes) - Matches recommendation
• Watching video lessons: 16:00 - 16:30 (30 minutes) - Matches recommendation
• Problem-solving: 17:00 - 17:30 (30 minutes) and 18:00 - 18:30 (30 minutes) = 60 minutes total - Matches recommendation
• Memorizing definitions: 15:00 - 15:30 (30 minutes) - Matches recommendation

Anna's schedule includes all recommended activities with the correct durations. Based on the analysis, Ivan's schedule is incorrect because he allocated only 30 minutes for problem-solving instead of the recommended 60 minutes.

Ответ: Иван