Hello everyone.
I am new to scuba diving, had my first go today ( what fun) doing PADI open water course.
I am having trouble answering one of the questions in the manual.
I hope some one here maybe able to work out the problem for me

The question is:
What is the minimum surface interval required between a dive to 20m /70feet for 29 minutes. followed by a dive to 14m/50feet for 39 minutes?
We can not get a answer????????????
I hope someone can help.
Thanks
Honey