Given that the start time is 5:15 am. It can be represented as,
Also given that the end time is 12:04 pm. It can be represented as.
The elapsed time (e) is equal to the difference between the end time and start time as given below,
Substitute the values,
Note that 04 minutes is greater than 15 minutes, so we have to borrow 1 hour from 12 hours and add it to the minutes,
Replace the value and perform the subtraction,
Thus, the required elapsed time is 6:49, that is, 6 hours and 49 minutes.