Answer
$ 59^{\circ} 43' $
Work Step by Step
$180^{\circ} $ - ($ 120^{\circ} 17') $
$180^{\circ} $ can also be written as $179^{\circ} 60' $ ( converting 1 degree to 60 minutes)
therefore the problem becomes-
$179^{\circ} 60' $ - $ 120^{\circ}17' $
$ 179^{\circ} 60' $
- $ 120^{\circ} 17' $
________
$ 59^{\circ} 43' $
Answer is $ 59^{\circ} 43' $