In jana's closet she has 5 pairs of black shoes and 11 pairs of leather shoes. two of her pairs of shoes are both black and leather. determine the total number of shoes that are either black, leather, or both

Here is their argument. given the obtuse angle x, we make a quadrilateral abcd with ∠dab = x, and ∠abc = 90◦, and ad = bc. say the perpendicular bisector to dc meets the perpendicular bisector to ab at p. then pa = pb and pc = pd. so the triangles pad and pbc have equal sides and are congruent. thus ∠pad = ∠pbc. but pab is isosceles, hence ∠pab = ∠pba. subtracting, gives x = ∠pad−∠pab = ∠pbc −∠pba = 90◦. this is a preposterous conclusion – just where is the mistake in the "proof" and why does the argument break down there?

What could explain what happened when the time was equal to 120 minutes

With both problems. a.s.a.p directions on photo ^