(a) 1/3 hour plus 1/2 hour is 5/6 hour. The LCD here is 6.
(b) That would be 7 times 5/6 hour, or 35/6 hours, or 5 5/6 hours.
(c) Convert 35/6 hours (from part b) into minutes:
35 hours 10 min 350 min
------------ * ----------------- = ------------- = 350 min
6 (1/6) hr 1