With a uniform electric field, flux go along parallel paths, then flux is therefore proportional to the cosine of the angle rotated.
0 degree rotation => cos(0)=1 => 100% of flux.
60 degrees rotation => cos(60) => 0.5 => how many % of flux?
Answer:
C
Step-by-step explanation:

150 minutes / day for a week
= (150 minutes / day) * (7 days / week)
= 150 * 7 minutes / week
= 1050 minutes / week
(1050 minutes / week) * (1 hour / 60 minutes)
= (1050 / 60) hours / week
= (105 / 6) hours / week
= 17.5 hours / week
You could also convert to hours first. 150 minutes = 2.5 hours * 7 days = 17.5 hours per week.