How to calculate HH:MM:SS?

Question

How to calculate HH:MM:SS in  coulumn data in below table

 

TABLE:

Overtime_HHMM

0:47:00

1:19:00

3:13:00

11:20:00

2:05:00

0:32:00

2:04:00

1:35:00

2:58:00

1:07:00

2:00:00

2:01:00

1:54:00

0:45:00

0:15:00

Total         33:55:00

Finally This Overtime_HHMM column  total  result is 33:55:00