Step-by-Step Time Calculation

To find out how long Garvita must wait, we need to determine three key pieces of information: the correct current time, the actual time the last bus departed, and the scheduled time for the next bus.

1. Determine the Correct Current Time

• The problem states that Garvita's watch shows 9:35 AM and it keeps the correct time.
• Therefore, the correct current time is 9:35 AM.

2. Determine the Actual Departure Time of the Last Bus

• Manya's watch showed the last bus left at 9:25 AM.
• However, Manya's watch is 5 minutes fast. This means the actual time was 5 minutes earlier than what her watch showed.
• Actual Departure Time = 9:25 AM - 5 minutes = 9:20 AM.

3. Determine the Next Bus's Departure Time

• The bus runs with a frequency of every 20 minutes.
• Since the last bus left at the correct time of 9:20 AM, the next bus will depart 20 minutes after that.
• Next Bus Departure Time = 9:20 AM + 20 minutes = 9:40 AM.

4. Calculate the Waiting Time

The waiting time is the difference between the next bus's departure time and the current correct time.

Waiting Time = 9:40 AM - 9:35 AM

Waiting Time = 5 minutes

Conclusion

Garvita must wait for 5 minutes to catch the next bus.