The constraint on time is
.. 75W +15M ≥ 300 . . . . . . . minutes
The constraint on paper is
.. 3W +M ≤ 20 . . . . . . . . . . . sheets of paper
The angle immediately below x makes up the third angle of the isosceles triangle whose base angles are 55°. That third angle and x are "vertical" angles, hence equal. The value of x can be found from the sum of angles of a triangle:
x + 55° + 55° = 180°
x = 70°
The appropriate choice is the 2nd one:
70°
Take 3 out of both of them
3(5x+2)
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.