Rajdhani Express starts from a station at 7:29 p.m. and reaches the next…

To add a duration to a 12-hour clock time, first convert the start time to 24-hour format, add the hours and minutes separately (carrying any minute sum of 60 or more into the hour count), reduce the total hours modulo 24, and finally convert that 24-hour result back to 12-hour format: hours 0-11 are a.m. and hours 12-23 are p.m., with 13-23 read as 1-11 p.m.

1. Write the start time 7:29 p.m. in 24-hour form: 19:29.

2. Add the minutes: 29 + 42 = 71 minutes = 1 hour 11 minutes, so carry 1 hour and keep 11 minutes.

3. Add the hours: 19 + 17 = 36, plus the 1 hour carried from the minutes = 37 hours.

4. Reduce 37 modulo 24: 37 - 24 = 13, so the 24-hour time is 13:11.

5. Convert 13:11 to 12-hour format: since 13 is in the 12-23 range, it is p.m., and 13 corresponds to 1, giving 1:11 p.m.

As an independent check, 24 hours after 7:29 p.m. is again 7:29 p.m. the next day. The given duration of 17 hours 42 minutes is 6 hours 18 minutes short of a full 24 hours, so subtracting 6 hours 18 minutes from 7:29 p.m. should give the same result: 7:29 p.m. minus 6 hours is 1:29 p.m., and minus the remaining 18 minutes gives 1:11 p.m. -- confirming the answer.