Ram leaves his house at 20 minutes to seven in the morning and reaches the house of Kunal in 25 minutes. They finish their breakfast in another 15 minutes and then leave together for their office, which takes another 35 minutes to reach. At what time do they leave the house of Kunal to go to their office?

Introduction / Context:
This question is a straightforward time calculation problem. It checks whether you can correctly interpret phrases like 20 minutes to seven, add travel and activity durations, and identify the exact clock time when a particular event occurs. These types of problems appear frequently in arithmetic reasoning sections of competitive exams.

Given Data / Assumptions:

• Ram leaves his house at 20 minutes to seven in the morning.
• 20 minutes to seven means 6:40 A.M.
• He takes 25 minutes to reach the house of Kunal.
• They spend 15 minutes on breakfast at Kunal's house.
• After breakfast they leave for their office and that final travel takes 35 minutes, but we are only asked about the time when they leave the house of Kunal.

Concept / Approach:
The core approach is to convert all time expressions into standard clock times and then add or subtract durations step by step. We carefully track the timeline: departure from Ram's house, arrival at Kunal's house, completion of breakfast, and final departure for the office. Since the question asks specifically for the departure time from the house of Kunal, we focus on the moment just after breakfast finishes.

Step-by-Step Solution:
Step 1: 20 minutes to seven means 7:00 A.M minus 20 minutes, which is 6:40 A.M.Step 2: Ram takes 25 minutes to reach Kunal, so arrival time is 6:40 A.M + 25 minutes = 7:05 A.M.Step 3: They spend 15 minutes having breakfast at Kunal's house.Step 4: Breakfast ends at 7:05 A.M + 15 minutes = 7:20 A.M.Step 5: Immediately after breakfast, they leave for their office. Therefore, the departure time from Kunal's house is 7:20 A.M.

Verification / Alternative check:
To verify, construct a full timeline including the last travel leg. From 7:20 A.M they take 35 minutes to reach the office, so they arrive at 7:55 A.M. This value is not directly needed for the answer, but it confirms the arithmetic is consistent. There are no hour crossings between 6:40 and 7:55 that would cause confusion, so the calculations remain simple and stable.

Why Other Options Are Wrong:
7:40 A.M would be 20 minutes after they leave Kunal's house, which does not match the 15 minute breakfast duration.7:45 A.M would imply a 40 minute breakfast, which contradicts the given 15 minutes.8:15 A.M is much too late and could be confused with the possible time of office arrival if calculations were done incorrectly.7:30 A.M assumes either a different departure time or incorrect addition of minutes.

Common Pitfalls:
Many students misinterpret 20 minutes to seven as 7:20 A.M instead of 6:40 A.M, which reverses the meaning of the phrase. Another error is mixing up which time the question is asking for, such as accidentally giving the office arrival time instead of the departure time from Kunal's house. Writing down the timeline in order and labelling each event is an effective way to avoid confusion.

Final Answer:
They leave the house of Kunal to go to their office at 7:20 A.M.