The constraint on time is
.. 75W +15M ≥ 300 . . . . . . . minutes
The constraint on paper is
.. 3W +M ≤ 20 . . . . . . . . . . . sheets of paper
RS Bisects QT means, it cuts QT in two equal halves, so QP would be equal to PT, as it is an isosceles triangle, one other side would be equal as well, so RP is equal to PS, Now, by ASA, we conclude the both mentioned triangles in the figure are congruent.
Hope this helps!
I believe the answer is 0.5
